Method and device for collecting products in iodine radioactive isotope dry production process

Abstract

The invention provides a product collection method and device in an iodine radioisotope dry production process, and the method comprises the steps: sealing an air inlet and an air outlet of a target piece, enabling a target material used for preparing iodine radioisotopes in the target piece to generate the iodine radioisotopes under neutron irradiation, and cooling the target piece to 30 DEG C or below after irradiation is completed; after the target piece is cooled, an air inlet of the target piece is communicated with an ozone generator and an air compressor, and an air outlet of the target piece is communicated with a trap; the reaction of the ozone with the iodine radioisotope in the target and the purging of the reaction product in the target by the compressed air are carried out alternately, thereby collecting the iodine radioisotope onto the trap. Compared with the prior art, the method and the device for collecting the product in the dry production process of the iodine radioactive isotope, provided by the invention, can realize efficient oxidation separation and trapping of the reactor irradiation iodine radioactive isotope under the condition of normal temperature, and the oxide of the oxidized iodine radioactive isotope is small in pipeline loss rate and high in product yield under the condition of normal temperature.

Description

Technical Field

[0001] The invention relates to the technical field of iodine radioisotope production, and in particular to a product collection method and device in a dry production process of iodine radioisotope. Background Art

[0002] 131 I is a very useful radionuclide. Reactor irradiation is an important process for producing radioisotope products. 131 I The main methods are irradiation of uranium targets and irradiation of tellurium targets. Due to the many side reactions of irradiated uranium-235 and the complex process conditions, it is rarely used. 131 Method I produces less waste, has no contamination from α impurities and other fission products, has high product purity, low production cost, and is widely used.

[0003] Preparation of irradiated tellurium target 131 I is divided into two processes: wet process and dry process. The wet process uses tellurium powder as the target material, dissolves it with a large amount of acid, and distills it to obtain the product. There are many radioactive waste liquids, which are difficult to handle and cumbersome to operate. The dry process uses TeO2 as the target material, and the product is obtained by high-temperature dry distillation after irradiation. It has the advantages of high yield, high radioactive concentration and radiochemical purity, short production time, less radioactive waste, safety and reliability, and has become the current 131 The main method of preparation of I.

[0004] Dry production 131 The process of I is to pour the activated tellurium dioxide into a quartz glass container (such as a quartz boat) and put it into the quartz glass tube of the distiller for high temperature (about 750°C) distillation. 131 I evaporates from the molten tellurium dioxide, is carried out of the distiller by the carrier gas, and is then absorbed by the dilute NaOH solution in the absorption bottle, thereby achieving 131 I separation and collection of products. Existing methods 131 I distillation collection process requires higher temperature to achieve 131 I Full volatilization of the product, especially in some low-temperature pipe sections, is more likely to occur 131 I deposition loss, resulting in low product yield and absorption 131 There is a risk of spillage of NaOH solution during transportation, which may cause the spread of radioactive contamination and is not easy to transport flexibly.

[0005] The above problems need to be solved urgently. Summary of the invention

[0006] The invention discloses a separation and collection method and device for products of iodine radioactive isotope dry distillation process, aiming to solve the technical problems existing in the prior art.

[0007] The present invention adopts the following technical solutions:

[0008] On the one hand, the present invention provides a product collection method for a dry production process of iodine radioactive isotopes, comprising: sealing an air inlet and an air outlet of a target, a target material for preparing iodine radioactive isotopes in the target to generate iodine radioactive isotopes under neutron irradiation, and cooling the target to below 30°C after the irradiation is completed; after the target is cooled, the air inlet of the target is connected to an ozone generator and an air compressor, and the air outlet of the target is connected to a collector; ozone in the ozone generator reacts with iodine radioactive isotopes in the target to generate reaction products, and compressed air in the air compressor sweeps the reaction products in the target to the collector, and the reaction of ozone with iodine radioactive isotopes in the target and the sweeping of the reaction products in the target by compressed air are performed alternately, so that the iodine radioactive isotopes are collected on the collector.

[0009] Preferably, the iodine radioisotope comprises 125 I or 131 I.

[0010] Preferably, the preparation 131 The target material of I is tellurium dioxide powder or a mixture of tellurium dioxide powder and activated carbon or a mixture of tellurium dioxide powder and molecular sieve;

[0011] Preferably, the preparation 125 The target material of I is high-purity xenon gas or a mixture of high-purity xenon gas and activated carbon or a mixture of high-purity xenon gas and molecular sieve.

[0012] Preferably, the concentration of ozone in the ozone generator is 100-300 mg / L;

[0013] And / or, the purge flow rate of ozone in the ozone generator is 2-5 L / min;

[0014] And / or, the reaction time of ozone and iodine radioisotope is 1-2h;

[0015] And / or, the number of reactions between ozone and iodine radioisotope is 2-5 times.

[0016] Preferably, the purge flow rate of the compressed air in the air compressor is 100-200 L / min;

[0017] And alternatively, the purge time of the compressed air in the air compressor is 30-60 minutes;

[0018] And / or, the compressed air in the air compressor is purged 2-5 times.

[0019] Preferably, the method further comprises: after collecting the iodine radioisotope on the trap, taking out the trap and immersing it in a NaOH solution for elution, wherein the CI of the trap in the NaOH solution - The leaching concentration of ions is less than 8ppm, SO4 2- The leaching concentration of ions is less than 60 ppm.

[0020] In a second aspect, the present invention provides a product collection device for a dry production process of iodine radioactive isotopes, comprising: an ozone generator; an air compressor; a target, wherein one end of the target is provided with an air inlet, and the other end of the target is provided with an air outlet, the air inlet of the target being respectively connected to the ozone generator and the air compressor; and a collector, wherein the collector is connected to the air outlet of the target.

[0021] Preferably, the collector comprises a high-efficiency glass fiber filter membrane and a filter membrane clamp, and the filter membrane clamp is detachably connected to the high-efficiency glass fiber filter membrane.

[0022] Preferably, it also includes: a first air inlet pipeline, which connects the ozone generator with the target; a second air inlet pipeline, which connects the air compressor with the target; a first air outlet pipeline, which connects the target with the trap; an iodine adsorber, which connects the iodine adsorber with the trap; and a ventilation system, which connects the iodine adsorber;

[0023] Preferably, the iodine adsorber is filled with impregnated activated carbon for purifying ozone and tail gas of compressed air.

[0024] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0025] The present invention mainly provides a product collection method and device for a dry production process of iodine radioactive isotopes. The collection method comprises: sealing an air inlet and an air outlet of a target, a target material for preparing iodine radioactive isotopes in the target generates iodine radioactive isotopes under neutron irradiation, and cooling the target to below 30°C after the irradiation is completed; after the target is cooled, connecting the air inlet of the target with an ozone generator and an air compressor, and connecting the air outlet of the target with a collector; ozone in the ozone generator reacts with iodine radioactive isotopes in the target to generate reaction products, and compressed air in the air compressor sweeps the reaction products in the target to the collector, and the reaction of ozone with iodine radioactive isotopes in the target and the sweeping of the reaction products in the target by compressed air are alternately performed, so that the iodine radioactive isotopes are collected on the collector. Compared with the prior art, the product collection method and device of the iodine radioactive isotope dry production process provided by the present invention can realize efficient oxidation separation and capture of irradiated iodine radioactive isotopes under normal temperature conditions, and the pipeline loss rate of the oxide of the iodine radioactive isotope after oxidation is small at normal temperature, and the product yield is high; and the oxide of the iodine radioactive isotope obtained by the method is solid, and the filter membrane after adsorbing the product has good chemical stability, is easy to transport and temporarily store in various work sections, and has a low risk of radioactive diffusion. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions explain the present invention and do not constitute improper limitations on the present invention. In the drawings:

[0027] Figure 1 A schematic structural diagram of a device for separating and collecting products of an iodine radioactive isotope dry distillation process provided in an embodiment of the present invention.

[0028] Reference numerals:

[0029] 10. Target; 101. Air inlet; 102. Air outlet; 103. Target material; 11. First air inlet duct; 12. Second air inlet duct; 13. First air outlet duct; 20. Ozone generator; 30. Air compressor; 40. Collector; 41. High-efficiency glass fiber filter membrane; 42. Filter membrane clamp; 50. Iodine adsorber; 60. Ventilation system. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or", unless the content clearly indicates otherwise.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a magnetic connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three or more, etc., unless otherwise clearly and specifically limited.

[0032] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In order to solve the problems existing in the prior art, on the one hand, the present invention provides a product collection method for the dry production process of iodine radioisotopes, comprising: sealing the air inlet 101 and the air outlet 102 of the target 10, the target material 103 for preparing iodine radioisotopes in the target 10 produces iodine radioisotopes under neutron irradiation, and cooling the target 10 to below 30° C. after the irradiation is completed; after the target 10 is cooled, the air inlet 101 of the target 10 is connected to the ozone generator 20 and the air compressor 30, and the air outlet 102 of the target 10 is connected to the ozone generator 20 and the air compressor 30, and ... inlet 101 of the target 10 is connected to the ozone generator 20 and the air compressor 30, and the air outlet 102 of the target 10 is connected to the ozone generator 20 and the air compressor 30, and the air inlet 101 of the target 1 The air port 102 is connected to the collector 40; the ozone in the ozone generator 20 reacts with the iodine radioisotope in the target 10 to generate a reaction product, and the compressed air in the air compressor 30 sweeps the reaction product in the target 10 to the collector 40, and the reaction of the ozone with the iodine radioisotope in the target 10 and the purging of the reaction product in the target by the compressed air are alternately performed, so that the iodine radioisotope is collected on the collector 40, and the gaseous iodine element produced after irradiation is more easily adsorbed on the wall of the chamber or the pipeline, and the gaseous iodine element produced after the ozone oxidation ... 131 I2O5, and then the irradiated 131 I2O5 is filtered onto the collector and finally 131 The invention relates to efficient collection of I products. The collection method can realize efficient oxidation separation and capture of irradiated iodine radioactive isotopes under room temperature conditions. The oxide of the oxidized iodine radioactive isotope has a small pipeline loss rate at room temperature and a high product yield.

[0034] Preferably, 131Taking I as an example, an appropriate target material is selected, and the target material 103 is loaded into the target piece and sent into the reactor or accelerator for irradiation; during the irradiation process, the tellurium target absorbs neutrons and undergoes β decay, thereby generating 131 I. The irradiation process will generate heat. To ensure the subsequent ozone oxidation efficiency, the temperature of the target 10 is first reduced to below 30°C to avoid ozone decomposition at high temperatures. The target can be cooled by natural cooling, circulating water cooling, heat pipe cooling and other methods.

[0035] The air inlet 101 of the target 10 is connected to the ozone generator 20 and the air compressor 30, and ozone is introduced to cause an oxidation reaction between the iodine radioisotopes generated by irradiation and the ozone, thereby generating oxides of the iodine radioisotopes. 131 I as an example, the ozone and irradiation produced 131 The reaction products of I are mainly 131 I2O5, and then introduce compressed gas to convert the reaction product into 131 I2O5 is purged and carried to the collector 40, thereby collecting the iodine radioactive isotopes on the collector 40. The collection method has a small loss rate through the pipeline at room temperature, which not only solves the problem that the existing method needs to maintain a high temperature during the dry distillation process. 131 I collects energy waste and avoids absorption 131 There is a risk of spillage of alkali solution in I, which may cause the spread of radioactive contamination and require flexible transportation.

[0036] In some preferred embodiments, the iodine radioisotope comprises 125 I or 131 I.

[0037] In some preferred embodiments, the preparation 131 The target material 103 of I is tellurium dioxide powder or a mixture of tellurium dioxide powder and activated carbon or a mixture of tellurium dioxide powder and molecular sieve.

[0038] Preferably, before irradiation, the target is prepared 131 The target material 103 of I is loaded with tellurium dioxide alone or mixed with porous materials (such as activated carbon, molecular sieve). The mixed loading of porous materials and tellurium dioxide can 131 I is adsorbed in the porous material, so that the subsequent oxidation reaction occurs on the surface of the porous material to further enhance the reaction process.

[0039] In some preferred embodiments, the preparation 125 The target material 103 of I is high-purity xenon gas or a mixture of high-purity xenon gas and activated carbon or a mixture of high-purity xenon gas and molecular sieve.

[0040] Similarly, the target is prepared 125 The target material 103 of I is filled with high-purity xenon gas alone or mixed with porous materials (such as activated carbon and molecular sieves). The mixed filling method of porous materials and high-purity xenon gas can 125 I is adsorbed in the porous material, so that the subsequent oxidation reaction occurs on the surface of the porous material to further enhance the reaction process.

[0041] In some preferred embodiments, the concentration of ozone in the ozone generator 20 is 100-300 mg / L;

[0042] And / or, the purge flow rate of ozone in the ozone generator 20 is 2-5 L / min;

[0043] And / or, the reaction time of ozone and iodine radioisotope is 1-2 hours;

[0044] And / or, the number of reactions of ozone with the iodine radioisotope is 2-5 times.

[0045] Preferably, the ozone-containing gas can be pure ozone gas or a mixed gas containing ozone gas mixed with one or more other gases. The concentration of ozone in the ozone-containing gas is 100-300 mg / L. By controlling the concentration of ozone, on the one hand, the waste of ozone is reduced and excessive emissions are avoided, while at the same time ensuring the smooth progress of the oxidation reaction.

[0046] In some preferred embodiments, the purge flow rate of the compressed air in the air compressor 30 is 100-200 L / min;

[0047] And alternatively, the purge time of the compressed air in the air compressor 30 is 30-60 minutes;

[0048] And / or, the compressed air in the air compressor 30 is purged 2-5 times.

[0049] Preferably, the flow rate of the ozone-containing gas is smaller than the purge flow rate of the compressed air. The small flow rate of ozone purge can achieve full reaction of ozone to ensure reaction efficiency, and on the other hand, reduce waste of ozone and take environmental protection into consideration; while the main function of the large flow rate of compressed air purge is to blow out the oxides of the iodine radioisotopes generated by the reaction, and finally achieve a high recovery rate;

[0050] In some preferred embodiments, after the compressed air in the air compressor 30 sweeps the reaction products in the target to the trap 40, the process further includes: taking out the trap 40 and immersing it in a NaOH solution for rinsing. - The leaching concentration of ions is less than 8ppm, SO4 2-The leaching concentration of ions is less than 60ppm.

[0051] In a second aspect, the present invention provides a product collection device for a dry production process of iodine radioactive isotopes, comprising: an ozone generator 20; an air compressor 30; a target 10, wherein an air inlet 101 is provided at one end of the target 10, and an air outlet 102 is provided at the other end of the target 10, and the air inlet 101 of the target is respectively connected to the ozone generator 20 and the air compressor 30; and a collector 40, wherein the collector 40 is connected to the air outlet 102 of the target 10.

[0052] Preferably, the ozone generator 20 is used to provide ozone gas, the air compressor 30 is used to provide compressed air, and the tellurium target is loaded into the target 10 and sent into the reactor or accelerator for irradiation; during the irradiation process, the tellurium target absorbs neutrons and undergoes β decay, thereby generating 131 I, or pass xenon target material into the target and send it into the reactor or accelerator for irradiation. During the irradiation process, the xenon target material absorbs neutrons and undergoes β decay, thereby generating 125 I, by compressing the gas 131 I2O5 or 125 The I2O5 is purged and carried to the trap 40, thereby collecting the iodine radioactive isotope on the trap 40.

[0053] In some preferred embodiments, the collector 40 includes a high-efficiency glass fiber filter membrane 41 and a filter membrane clamp 42. The filter membrane clamp 42 is detachably connected to the high-efficiency glass fiber filter membrane 41, and the filter membrane clamp 42 is respectively connected to the target 10 and the iodine adsorber 50.

[0054] Specifically, the reaction product is compressed by gas 131 I2O5 or 125 I2O5 is purged and carried onto the high-efficiency glass fiber filter 41. The high-efficiency glass fiber filter 41 and the filter clamp 42 are detachably connected, so that the collector 40 can be quickly disassembled for subsequent 131 I label production when it is necessary to transfer the collected reaction products 131 I2O5 or 125 When I2O5 is used, the high-efficiency glass fiber filter 41 is directly removed from the filter membrane clip 42, and the transportation and temporary storage of each section can be carried out. The risk of radioactive diffusion is small. When the radioactive isotope needs to be used, the high-efficiency glass fiber filter is removed from the filter membrane clip, and the high-efficiency glass fiber filter 41 is immersed in NaOH solution for elution. After elution, the product is obtained. 131 I or 125 I. CI of high efficiency glass fiber membrane 41 in NaOH - The leaching concentration of ions is less than 8ppm, SO4 2- The leaching concentration of ions is less than 60ppm

[0055] In some preferred embodiments, it also includes: a first air inlet pipe 11, which connects the ozone generator 20 with the target 10; a second air inlet pipe 12, which connects the air compressor 30 with the target 10; a first air outlet pipe 13, which connects the target 10 with the collector 40; an iodine adsorber 50, which is connected to the collector 40; and a ventilation system 60, which is connected to the iodine adsorber 50.

[0056] In some preferred embodiments, the iodine adsorber 50 is filled with impregnated activated carbon for purifying ozone and exhaust gas of compressed air. After being purified by the iodine adsorber 50, the exhaust gas such as ozone and compressed air can be discharged into the ventilation system 60 of the factory.

[0057] Example 1

[0058] Take 5g of tellurium dioxide powder as the target material and load it into the target alone. Seal the air inlet and outlet on the target. 130 Te(n,γ) 131 Te(β-) 131 I nuclear physics reaction obtained 131 I, obtained by gamma spectrometer (Maestro-32) 131 The activity of I is 200 MBq.

[0059] Because the target 131 Since heat is released during the nuclear physical reaction of I, the target is cooled to 25°C by natural cooling, and then the air inlet of the cooled target is connected to the ozone generator through a first air inlet pipe, the air inlet of the cooled target is connected to the air compressor through a second air inlet pipe, and the air outlet of the cooled target is connected to the collector through the first air outlet pipe, and the collector is connected to the iodine adsorber and the ventilation system in sequence through pipelines.

[0060] Turn on the ozone generator, control the ozone concentration at 200 mg / L and blow the ozone into the target at a flow rate of 2 L / min. 131 I undergoes oxidation reaction to generate 131 After the I2O5 particles reacted for 2 h, the air compressor was switched on to purge the inside of the target at a flow rate of 160 L / min for 1 h. 131 The I2O5 particles are carried by compressed air to the high-efficiency glass fiber filter of the collector. The target is purged with ozone and compressed air alternately for 5 times. 131 I2O5 collection, after the collection is completed, the intercepted 131The high-efficiency glass fiber filter of I oxide was taken out and immersed in 15 ml of NaOH solution for two rinses. - The leaching concentration of ions is less than 8ppm, SO4 2- The leaching concentration of ions is less than 60ppm, and the collected 131 The total activity of I2O5 is 197.6MBq (the total activity is the sum of the first elution activity and the second elution activity). 131 The collection rate of I is 98.8%, and the collection rate is 131 Total I2O5 activity and the activity obtained by nuclear physics reactions 131 The activity ratio of I.

[0061] Example 2

[0062] Take 5g of tellurium dioxide powder and 200g of activated carbon as target materials and load them into the target separately. The specific surface area of ​​activated carbon is greater than 1500m 2 / g, seal the air inlet and outlet on the target, and use 130 Te(n,γ) 131 Te(β-) 131 I nuclear physics reaction obtained 131 I, obtained by gamma spectrometer (Maestro-32) 131 The activity of I is 200 MBq.

[0063] Because the target 131 Since heat is released during the nuclear physical reaction of I, the target is cooled to 25°C by natural cooling, and then the air inlet of the cooled target is connected to the ozone generator through a first air inlet pipe, the air inlet of the cooled target is connected to the air compressor through a second air inlet pipe, and the air outlet of the cooled target is connected to the collector through the first air outlet pipe, and the collector is connected to the iodine adsorber and the ventilation system in sequence through pipelines.

[0064] Turn on the ozone generator, control the ozone concentration at 200 mg / L and blow the ozone into the target at a flow rate of 2 L / min. 131 I undergoes oxidation reaction to generate 131 After the I2O5 particles reacted for 1.5 h, the air compressor was switched on to purge the inside of the target at a flow rate of 200 L / min for 1 h. 131 The I2O5 particles are carried by compressed air to the high-efficiency glass fiber filter of the collector. The target is purged with ozone and compressed air alternately for 5 times. 131 I2O5 collection, after the collection is completed, the intercepted 131The high-efficiency glass fiber filter of I oxide was taken out and immersed in 15 ml of NaOH solution for two rinses. - The leaching concentration of ions is less than 8ppm, SO4 2- The leaching concentration of ions is less than 60ppm, and the collected 131 The total activity of I2O5 is 199MBq (the total activity is the sum of the first elution activity and the second elution activity). 131 The collection rate of I is 99.5%, and the collection rate is 131 Total I2O5 activity and the activity obtained by nuclear physics reactions 131 The activity ratio of I.

[0065] Example 3

[0066] Take 5g of tellurium dioxide powder and 200g of molecular sieve as target materials and load them into the target separately. The molecular sieve seals the air inlet and outlet on the target. At room temperature, use 130 Te(n,γ) 131 Te(β-) 131 I nuclear physics reaction obtained 131 I, obtained by gamma spectrometer (Maestro-32) 131 The activity of I is 200 MBq.

[0067] Because the target 131 Since heat is released during the nuclear physical reaction of I, the target is cooled to 25°C by natural cooling, and then the air inlet of the cooled target is connected to the ozone generator through a first air inlet pipe, the air inlet of the cooled target is connected to the air compressor through a second air inlet pipe, and the air outlet of the cooled target is connected to the collector through the first air outlet pipe, and the collector is connected to the iodine adsorber and the ventilation system in sequence through pipelines.

[0068] Turn on the ozone generator, control the ozone concentration at 200 mg / L and blow the ozone into the target at a flow rate of 2 L / min. 131 I undergoes oxidation reaction to generate 131 After the I2O5 particles reacted for 1.5 h, the air compressor was switched on to purge the inside of the target at a flow rate of 200 L / min for 1 h. 131 The I2O5 particles are carried by compressed air to the high-efficiency glass fiber filter of the collector. The target is purged with ozone and compressed air alternately for 5 times. 131 I2O5 collection, after the collection is completed, the intercepted 131The high-efficiency glass fiber filter of I oxide was taken out and immersed in 15 ml of NaOH solution for two rinses. - The leaching concentration of ions is less than 8ppm, SO4 2- The leaching concentration of ions is less than 60ppm, and the collected 131 The total activity of I2O5 is 199MBq (the total activity is the sum of the first elution activity and the second elution activity). 131 The collection rate of I is 99.5%, and the collection rate is 131 Total I2O5 activity and the activity obtained by nuclear physics reactions 131 The activity ratio of I.

[0069] Example 4

[0070] 100 mL of xenon (Xe) was introduced as the target material and placed inside the target. The inlet and outlet of the target were sealed and radiated at room temperature to obtain 125 I, obtained by gamma spectrometer (Maestro-32) 125 The activity of I is 100 MBq.

[0071] Because the target 125 I releases heat during the radiation process, so the target is cooled to 25°C by natural cooling, and then the air inlet of the cooled target is connected to the ozone generator through the first air inlet pipe, the air inlet of the cooled target is connected to the air compressor through the second air inlet pipe, and the air outlet of the cooled target is connected to the collector through the first air outlet pipe, and the collector is connected to the iodine adsorber and the ventilation system in sequence through pipelines.

[0072] Turn on the ozone generator, control the ozone concentration at 200 mg / L and blow the ozone into the target at a flow rate of 2 L / min. 125 I undergoes oxidation reaction to generate 131 After the I2O5 particles reacted for 1.5 h, the air compressor was switched on to purge the inside of the target at a flow rate of 200 L / min for 1 h. 125 The I2O5 particles are carried by compressed air to the high-efficiency glass fiber filter of the collector. The target is purged with ozone and compressed air alternately for 5 times. 125 I2O5 collection, after the collection is completed, the intercepted 125 The high-efficiency glass fiber filter of I oxide was taken out and immersed in 15 ml of NaOH solution for two rinses. - The leaching concentration of ions is less than 8ppm, SO4 2-The leaching concentration of ions is less than 60ppm, and the collected 125 The total activity of I2O5 is 98.3MBq (the total activity is the sum of the first elution activity and the second elution activity). 125 The collection rate of I is 98.3%, and the collection rate is 125 Total I2O5 activity and the activity obtained by nuclear physics reactions 125 The activity ratio of I.

[0073] Comparative Example 1

[0074] Tellurium dioxide with a total activity of 370MBq is placed in a quartz glass container (quartz boat), and the quartz boat containing the target is placed in a retort furnace. The heating temperature of the retort furnace is adjusted by a control system, heated to 730°C, and distilled for 2.5 hours to melt the tellurium dioxide and release iodine-131 gas.

[0075] A carrier gas (nitrogen or argon) is introduced into the retort at 40 mL / min, and the evaporated iodine-131 gas is carried out of the retort by the carrier gas for subsequent separation treatment.

[0076] Iodine-131 gas is absorbed by the dilute NaOH solution in the absorption bottle to form Na 131 I solution product, for purification; tail gas through the total loading of 0.75kg two-stage activated carbon column adsorption, measurement of the collected 131 The total activity of I is 358.9MBq. It can be calculated that 131 The collection rate of I was 97.0%.

[0077] Comparative Example 2

[0078] A total of 50 g of natural xenon (Xe) gas was placed in four target containers, each with a volume of 100 ml. High flux reactor irradiation. During the reactor irradiation process, the main nuclear reaction is: 124 Xe(n,γ) 125 XE 125 I. After cooling for 50-60 days, freeze the target with liquid nitrogen for 20 minutes and take it out. Use a punch to quickly punch a hole on the target container. After the xenon gas evaporates, pour 100ml of 0.1mol / L NaOH solution containing a reducing agent into each well and dissolve it for 1-2h. Transfer the solution to 125 I in the chemical separation device and the bottle, with sulfuric acid to neutralize to pH <6, and then the solution at a flow rate of 5-6ml / min PCC column adsorption, sample the feed liquid and effluent before and after the column 125I content. Wash PCC with 100 ml of distilled water, and then wash the column twice with 15 ml of 0.1 mol / L NaOH solution at a flow rate of 2-3 ml / min. Finally, neutralize with phosphoric acid to a pH of 7-9, and measure with a gamma spectrometer (Maestro-32). 125 The activity of the liquid I is 187.15MBq, and the activity after NaOH elution is 182.25MBq. It can be calculated that 125 The collection rate of I was 97.3%.

[0079] Table 1 Collection rate comparison table of embodiment and comparative example

[0080]

[0081] Comparative Document 1 is to collect iodine radioactive isotopes through existing technology, use TeO2 as target material, and obtain products through high-temperature dry distillation after irradiation. Specifically, a quartz boat containing the irradiated target material is placed in a dry distillation furnace, and the dry distillation furnace starts to heat up, and the furnace is heated up. When the temperature rises to 750-800°C, constant temperature heating is performed, and tellurium dioxide melts, releasing tellurium dioxide vapor and iodine vapor. Nitrogen or argon is then used to guide the tellurium oxide vapor and iodine vapor out of the dry distillation furnace for subsequent separation treatment. In the subsequent separation treatment, it is easy to occur in the low-temperature pipe section. 131 I deposition loss results in low product yield. In addition, since the released iodine vapor is elemental iodine, it is necessary to 131 I is absorbed in a NaOH solution and then transported. There is a risk of spillage during the transportation process, which may cause the spread of radioactive contamination.

[0082] As shown in Table 1, the 131 I and 125 The collection rate of I is above 98%. Compared with the comparative document 1, the embodiments 1-3 realize efficient oxidation separation and collection under normal temperature conditions after irradiation. 131 The main reaction products are 131 I2O5, produced by irradiation 125 The main reaction products are 125 I2O5, the oxide has good stability, low pipeline loss rate at room temperature, and higher product yield; the reaction products in the target are compressed by the compressed gas in the air compressor 131 I2O5 or 125 I2O5 is purged onto the high-efficiency glass fiber filter of the collector. The high-efficiency glass fiber filter is detachably connected to the filter clamp. When the radioactive isotope is needed, the high-efficiency glass fiber filter is removed from the filter clamp and immersed in NaOH solution for elution. The product is obtained after elution. 131 I or 125I. The oxide of the iodine radioisotope collected by this collection method is solid, and the high-efficiency glass fiber filter membrane after adsorbing the iodine radioisotope has good chemical stability, is easy to transport and temporarily store in various work sections, and has a low risk of radioactive diffusion.

[0083] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for collecting products in a dry process for producing radioactive iodine isotopes, characterized in that: include: The air inlet and the air outlet of the target are sealed, the target material for preparing iodine radioisotopes in the target generates iodine radioisotopes under neutron irradiation, and the target is cooled to below 30° C. after the irradiation is completed; After the target is cooled, the air inlet of the target is connected to the ozone generator and the air compressor, and the air outlet of the target is connected to the collector; The ozone in the ozone generator reacts with the iodine radioactive isotopes in the target to generate reaction products, and the compressed air in the air compressor sweeps the reaction products in the target to the collector. The reaction of ozone with the iodine radioactive isotopes in the target and the sweeping of the reaction products in the target by compressed air are performed alternately, thereby collecting the iodine radioactive isotopes on the collector.

2. The method according to claim 1, characterized in that The iodine radioisotopes include 125 I or 131 I.

3. The method according to claim 2, characterized in that The preparation 131 The target material of I is tellurium dioxide powder or a mixture of tellurium dioxide powder and activated carbon or a mixture of tellurium dioxide powder and molecular sieve.

4. The method according to claim 2, characterized in that: The preparation 125 The target material of I is high-purity xenon gas or a mixture of high-purity xenon gas and activated carbon or a mixture of high-purity xenon gas and molecular sieve.

5. The method according to claim 1 or 2, characterized in that: The concentration of ozone in the ozone generator is 100-300 mg / L; And / or, the purge flow rate of ozone in the ozone generator is 2-5 L / min; And / or, the reaction time of ozone and iodine radioisotope is 1-2h; And / or, the number of reactions between ozone and iodine radioisotope is 2-5 times.

6. The method according to claim 1 or 2, characterized in that: The purge flow rate of the compressed air in the air compressor is 100-200L / min; And alternatively, the purge time of the compressed air in the air compressor is 30-60 minutes; And / or, the compressed air in the air compressor is purged 2-5 times.

7. The method according to claim 1, characterized in that The method further comprises: after collecting the iodine radioisotope on the trap, taking out the trap and immersing it in a NaOH solution for elution; - The leaching concentration of ions is less than 8ppm, SO4 2- The leaching concentration of ions is less than 60 ppm.

8. A product collection device for the dry production process of iodine radioisotopes, characterized in that: include: Ozone generator; Air compressor; A target, wherein one end of the target is provided with an air inlet, and the other end of the target is provided with an air outlet, and the air inlet of the target is respectively connected to the ozone generator and the air compressor; A collector is communicated with the gas outlet of the target.

9. The device according to claim 8, characterized in that The collector comprises a high-efficiency glass fiber filter membrane and a filter membrane clip, and the filter membrane clip is detachably connected to the high-efficiency glass fiber filter membrane.

10. The device according to claim 8, characterized in that Also includes: a first air inlet pipeline, the first air inlet pipeline connects the ozone generator with the target; a second air inlet pipeline, the second air inlet pipeline connects the air compressor with the target; a first air outlet pipeline, the first air outlet pipeline connects the target with the trap; an iodine adsorber, the iodine adsorber is connected with the trap; a ventilation system, the ventilation system is connected with the iodine adsorber; Preferably, the iodine adsorber is filled with impregnated activated carbon for purifying ozone and tail gas of compressed air.

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