CN211988035U - Extraction from dissolved irradiated uranium target tail gas133Xe、135Xe、85Kr's device - Google Patents
Extraction from dissolved irradiated uranium target tail gas133Xe、135Xe、85Kr's device Download PDFInfo
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- CN211988035U CN211988035U CN202020032448.2U CN202020032448U CN211988035U CN 211988035 U CN211988035 U CN 211988035U CN 202020032448 U CN202020032448 U CN 202020032448U CN 211988035 U CN211988035 U CN 211988035U
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Abstract
The disclosure belongs to the field of radionuclide preparation, and particularly relates to extraction from dissolved irradiated uranium target tail gas133Xe、135Xe、85The apparatus of Kr, the apparatus comprising: the device comprises a gas blowing cylinder, a dissolver, a low-temperature absorption purification column, a xenon-krypton separation column, a krypton purification column, a xenon purification column, a pure krypton collector, a krypton product split bottle, a pure xenon collector, a xenon product split bottle and a gas storage tank; thus, radioactive inert gas can be recovered, separated and purified from tail gas treatment, and a beneficial radioactive isotope product is prepared, so that fission products can be more and beneficially applied in economic value.
Description
Technical Field
The disclosure belongs to the field of radionuclide preparation, and particularly relates to extraction from dissolved irradiated uranium target tail gas133Xe、135Xe、85The apparatus of Kr.
Background
99mTc drugs are the most widely used radiodiagnostic drugs in modern nuclear medicine, and the nuclides are generally artificial radionuclides99Mo decays to obtain，99The half life of Mo is 66 h. At present, the world99The main source of Mo is generated by uranium-235 fission reaction through reactor irradiation99Mo, uranium target (235U) is subjected to fission reaction under the action of thermal neutrons after being stacked,235the U reaction cross-section is 586 b. Generating99The Mo fission reaction equation is:
235U(nf)236U→99Mo+134Sn+3n
extracting and purifying fission products from the uranium targets through a complex recovery process after the uranium targets are irradiated99Mo to obtain high purity medical use99Mo。
235U is subjected to fission reaction under the action of thermal neutrons to generate fission99In the presence of Mo99Mo, 6.1% by weight of the fission product, and hundreds of other radioactive fission products, in which 1 inert gas atom (xenon, krypton) is formed for every 4 atoms of uranium fission. The inert gases produced are mainly:133Xe、135xe and85kr, fission equation:
235U(nf)236U→133Xe+101Sr+2n
235U(nf)236U→135Xe+99Sr+2n
235U(nf)236U→85Kr+148Ba+3n
wherein: in the fission products, the molecular structure of the fission product,133the content of Xe is 6.77% (half-life period is 5.24 days, irradiation energy is 346keV, beta)-A ray),135the content of Xe is 6.63% (half-life period 9.14 hours, irradiation energy 901keV, beta)-A ray),85the content of Kr is 0.28% (half-life period is 3.93 days, irradiation energy is 687keV, beta)-A ray).
The gasification heat energy of the produced inert gases xenon and krypton is low, and is respectively as follows: 12.63KJ/mol and 9.029KJ/mol, very volatile, but with xenon and krypton atomic diameters (respectively)
And
) Specific diameter of uranium atom
Much larger, and difficult to move in the crystal lattice of uranium, and exists in the form of solid solution in the target235In U, the target is released immediately when the irradiated target is dissolved.
133Xe and85kr has beneficial applications in both medical and industrial applications.133Xe can be made into normal saline injection for diagnosing pulmonary function (including emphysema, acute pneumonia, bronchial asthma, pulmonary embolism), and measuring blood flow of myocardium, brain, and limbs.85Kr can also be used as a tracer for determining the blood flow condition of each organ in medical diagnosis. In industry85Kr is used for activating components in spontaneous light sources (airport runway and coal mine lighting), gas tracers (measuring gas flow rate and the like), nondestructive inspection, thermoelectric generator heat sources, dynamic energy conversion and the like.
Therefore, the target after irradiation is dissolved, and meanwhile, the inert gases xenon and krypton in the generated radioactive gas are separated and collected, so that the inert gas generated by fission is beneficially applied.
133Xe、135Xe、85Kr is colorless and tasteless inert gas, and the chemical property of the inert gas is determined by the atomic structure of the Kr and is stable, the Kr shows that the Kr is very inactive, the Kr hardly reacts with other substances, and is not easily soluble in water and other solution reagents, and a small amount of physical adsorption can be carried out on adsorbents such as activated carbon, molecular sieves and the like. But the physical property of the inert gas is almost ideal gas under the standard state, and the separation and purification device is designed and manufactured by utilizing the physical property of radioactive inert gas, so that the radioactive substances in fission products can be more applied.
SUMMERY OF THE UTILITY MODEL
Objects of the invention
In order to overcome the deficiencies of the prior art, the present disclosure provides a method for extracting from dissolved irradiated uranium target tail gas133Xe、135Xe、85The apparatus of Kr.
(II) technical scheme
Extraction from dissolved irradiated uranium target tail gas133Xe、135Xe、85The apparatus of Kr, the apparatus comprising: the device comprises a gas blowing cylinder, a dissolver, a low-temperature absorption purification column, a xenon-krypton separation column, a krypton purification column, a xenon purification column, a pure krypton collector, a krypton product split bottle, a pure xenon collector, a xenon product split bottle and a gas storage tank;
wherein the gas blowing bottle is connected with the dissolver through a pipeline, and the connecting pipeline of the gas blowing bottle and the dissolver extends into the bottom of the dissolver;
the dissolver is connected with the gas storage tank through a pipeline; the air storage tank is provided with an exhaust pipeline;
the inlet and outlet of the low-temperature absorption purification column are connected to a connecting pipeline of the dissolver and the gas storage tank through a pipeline;
the inlet and outlet of the xenon-krypton separation column are connected to a connecting pipeline of the dissolver and the gas storage tank through a pipeline; the outlet of the xenon-krypton separation column is respectively connected with the krypton purification column and the xenon purification column through pipelines;
the outlet of the krypton purification column is connected with a pure krypton collector through a pipeline; the pure krypton collector is connected to a connecting pipeline of the dissolver and the gas storage tank through a pipeline, and is connected with the krypton product split bottle through a pipeline;
the outlet of the xenon purification column is connected with a pure xenon collector through a pipeline; and the pure xenon collector is connected to the connecting pipeline of the dissolver and the gas storage tank through a pipeline, and is connected with the xenon product split charging bottle through a pipeline.
A valve is arranged on a connecting pipeline of the gas blowing cylinder and the dissolver; valves are arranged at the outlet of the dissolver and the inlet of the gas storage tank through connecting pipelines of the dissolver and the gas storage tank;
valves are arranged on the inlet and outlet pipelines of the low-temperature absorption purification column; a valve is arranged between the inlet and the outlet of the low-temperature absorption purification column;
valves are arranged on inlet and outlet pipelines of the xenon-krypton separation column; a valve is arranged between the inlet and the outlet of the xenon-krypton separation column;
valves are arranged on the connecting pipelines of the outlet of the xenon-krypton separation column, the krypton purification column and the xenon purification column;
a valve is arranged on a connecting pipeline between the krypton purification column and the pure krypton collector; a valve is arranged on an outlet pipeline of the pure krypton collector;
a valve is arranged on a connecting pipeline of the xenon purification column and the pure xenon collector; a valve is arranged on an outlet pipeline of the pure xenon collector;
the exhaust pipeline of the gas storage tank is provided with a valve.
The low-temperature absorption purification column is filled with an adsorbent; wherein the adsorbent is molecular sieve or active carbon.
The low-temperature absorption purification column and the xenon-krypton separation column are positioned in a cold trap; wherein the cold trap is filled with a refrigerant.
The low-temperature absorption purification column is a U-shaped tube, a convolution tube or a needle tube.
The low-temperature absorption purification column and the cold trap are in an all-metal sealed environment.
The number of the low-temperature absorption purification columns is more than or equal to 1.
Heaters are arranged outside the krypton purification column and the xenon purification column.
Pressure gauges are arranged on the gas blowing cylinder, the dissolver and the gas storage tank.
(III) advantageous effects
Extraction from irradiated uranium target tail gas of the present disclosure133Xe、135Xe and85the device for the inert gas such as Kr can recover, separate and purify radioactive inert gas from tail gas treatment to prepare beneficial radioactive isotope products, so that fission products can be more and beneficially applied in economic value.
Meanwhile, because radioactive inert gas in fission products is stable in chemical property and difficult to combine with other elements to be adsorbed, the radioactive inert gas can cause radioactive pollution to the environment after being released, and the method extracts the radioactive inert gas from the irradiated uranium target tail gas133Xe、135Xe and85apparatus for producing inert gas such as Kr utilizes difference in physical properties of inert gasThe mixture is separated, so that the radioactive inert gas can be completely absorbed and purified, and the environmental pollution is avoided.
Drawings
FIG. 1 is a process for extracting uranium from dissolved and irradiated uranium target tail gas133Xe、135Xe and85a schematic view of an apparatus for producing an inert gas such as Kr;
FIG. 2 is a schematic view of the U-shaped tube structure of the cryogenic absorption purification column 3 of FIG. 1;
FIG. 3 is a schematic view of the convoluted tube structure of the cryogenic absorption purification column 3 of FIG. 1;
FIG. 4 is a schematic diagram of the needle-shaped tube structure of the cryogenic absorption purification column 3 of FIG. 1;
wherein 1, a gas drum; 2, a dissolver; 3, low-temperature absorption purification column; 4. 6, cold trap; a 5 xenon krypton separation column; 8 krypton purification column; 9. 11 a heater; a 10 xenon purification column; a 12 pure krypton collector; 13, subpackaging and bottling krypton products; 15 a pure xenon collector; subpackaging 16 xenon products into bottles; 17 an air storage tank; 7. 14, 16, 18, 19, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 valves; 20. 32 and 33 pressure gauges.
Detailed Description
To better illustrate the present disclosure, an extraction from dissolved irradiated uranium tail gas133Xe、135Xe、85The apparatus of Kr, in conjunction with the specific embodiments, is described in detail as follows:
fission of fuel99Production of Mo, first of all from235Placing the target made of U into a reactor, irradiating for a certain time, taking out, transferring into a shielded hot room, placing into a dissolver in an all-metal closed environment for dissolving, and then dissolving235Extracting and purifying fission products after dissolving U target99And Mo. While the target is dissolved, the tail gas generated in the dissolving process is treated133Xe、135Xe、85Timely extracting and collecting Kr, and then extracting and collecting133Xe、135Xe、85From which Kr is separated and collected separately.
As shown in figure 1, according to the design scheme, the extraction method disclosed by the invention is used for extracting the tail gas from dissolving and irradiating the uranium target133Xe、135Xe、85The device of Kr is a totally-enclosed system made of stainless steel and consists of a low-temperature purification part, a chemical treatment part and a tail gas absorption part.
The device includes: the device comprises a gas blowing cylinder 1, a dissolver 2, a low-temperature absorption purification column 3, a xenon krypton separation column 5, a krypton purification column 8, a xenon purification column 10, a pure krypton collector 12, a krypton product split bottle 13, a pure xenon collector 15, a xenon product split bottle 16 and a gas storage tank 17.
The low-temperature purification part comprises a low-temperature absorption purification column 3 and a cold trap 4, wherein the low-temperature absorption purification column 3 is filled with a proper adsorbent, such as a specific molecular sieve or activated carbon, for adsorbing and slowing down the flow rate of the inert gas in the tail gas so as to be beneficial to adsorbing and collecting the inert gas, meanwhile, a refrigerant is added into the cold trap 4, and the refrigerant can be selected from liquid nitrogen or dry ice and the like.
Gas generated by dissolution flows in from an inlet of the low-temperature absorption purification column 3, flows out from an outlet after passing through the column, inert gas in the gas is adsorbed and enriched in the low-temperature absorption purification column 3, and other gas is collected in the gas storage tank 17;
for different fission99Requirement for Mo production capacity, irradiated per production235The quantity of the U target pieces is different, the quantity of inert gases generated by production and dissolution is different, the flow rate of the gases is controlled by a valve, the gases flow through the low-temperature absorption purification column 3 at a certain speed, and in order to ensure the total absorption of the radioactive gases, the low-temperature absorption purification column 3 can adopt various columns such as a U-shaped tube (shown in figure 2), a convoluted tube (shown in figure 3), a needle-shaped tube (shown in figure 4) and the like, so that the detention time of the gases in the column is prolonged, and the purpose of fully absorbing the inert gases is achieved. Meanwhile, the adoption of the U-shaped tube or the needle-shaped tube low-temperature absorption purification column can lay a foundation for the preparation of subsequent inert gas products, so that the inert gas can be resolved and separated in the low-temperature absorption purification column 3, and the purification and the split charging are more convenient.
When the quantity of dissolved and irradiated uranium target tail gas is large, a plurality of low-temperature absorption purification columns 3 can be connected in series to ensure complete absorption and purification of radioactive inert gas.
Wherein the chemical treatment part comprises a xenon krypton separation column 5, a krypton purification column 8, a pure krypton collector 12, a xenon purification column 10 and a pure xenon collector 15; collecting the radioactive inert gas enriched in the low-temperature absorption purification column 3, separating krypton from the gas through different freezing points by the xenon krypton separation column 5, purifying the gas on the krypton purification column 8 through low-temperature purification, and collecting the purified pure krypton in the pure krypton collector 12; meanwhile, the xenon separated from the xenon krypton separation column 5 is conveyed to a xenon purification column 10 for purification, and the purified xenon is collected in a pure xenon collector 15.
The tail gas absorption part comprises a gas storage tank 17, and the whole set of tail gas is extracted from dissolved and irradiated uranium target tail gas133Xe、135Xe and85tail gas generated in each link of the Kr device is collected in the gas storage tank 17 in a centralized manner, and is discharged after passing detection.
By adopting the device, all the valves are in a closed state initially, the valve 31 is opened to blow gas into the dissolver 2, and the inert fission gases xenon and krypton released by dissolving the uranium target are expelled from the dissolving liquid. The valves 30, 29, 27, 25 and 19 are opened to guide the gas to flow to the gas storage tank 17, the inert gases such as xenon and krypton and other radioactive gases generated by fission are collected in the low-temperature absorption purification column 3, and the rest tail gas enters the gas storage tank 17 to be stored.
After dissolving the uranium target, the valves 31, 30, 29 and 25 are closed, the inert gases xenon and krypton are separated in the low-temperature absorption purification column 3, the valves 26 and 24 are opened, and the separated xenon and krypton are collected in the xenon-krypton separation column 5. The valves 26 and 24 are closed, xenon and krypton in the xenon-krypton separation column 5 are separated, the valve 23 is opened to collect the separated krypton in the krypton purification column 8 for purification, and the valve 23 is opened to collect the separated xenon in the xenon purification column 10 for purification.
After the purification is finished, the valve 23 and the valve 7 are closed, the krypton purification column 8 and the xenon purification column 10 are heated respectively, the purified krypton and xenon are expelled, the valve 22 is opened, the krypton in the krypton purification column 8 is transferred to the pure krypton collector 12, and the product is subpackaged. The valve 14 is opened to transfer the xenon in the xenon purification column 10 to the pure xenon collector 15 for product split charging. The tail gas generated in the purification and split charging process is completely collected in the gas storage tank 17. And closing all valves after the work is finished.
It will be apparent to those skilled in the art that various changes and modifications can be made in the present disclosure without departing from the spirit and scope of the disclosure. Thus, if such modifications and variations to the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, it is intended that the present disclosure also encompass such modifications and variations. The foregoing examples or embodiments are merely illustrative of the present disclosure, which may be embodied in other specific forms or in other specific forms without departing from the spirit or essential characteristics thereof. The described embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. The scope of the disclosure should be indicated by the appended claims, and any changes that are equivalent to the intent and scope of the claims are intended to be included within the scope of the disclosure.
Claims (9)
1. Extraction from dissolved irradiated uranium target tail gas133Xe、135Xe、85Kr's apparatus, characterized in that the apparatus comprises: the device comprises a gas blowing cylinder (1), a dissolver (2), a low-temperature absorption purification column (3), a xenon krypton separation column (5), a krypton purification column (8), a xenon purification column (10), a pure krypton collector (12), a krypton product split bottle (13), a pure xenon collector (15), a xenon product split bottle (16) and a gas storage tank (17);
wherein the gas blowing bottle (1) is connected with the dissolver (2) through a pipeline, and the connecting pipeline of the gas blowing bottle (1) and the dissolver (2) extends into the bottom of the dissolver (2);
the dissolver (2) is connected with the gas storage tank (17) through a pipeline; the air storage tank (17) is provided with an exhaust pipeline;
the inlet and outlet of the low-temperature absorption purification column (3) are connected to a connecting pipeline of the dissolver (2) and the gas storage tank (17) through pipelines;
the inlet and outlet of the xenon krypton separation column (5) are connected to a connecting pipeline of the dissolver (2) and the gas storage tank (17) through a pipeline; and the outlet of the xenon-krypton separation column (5) is respectively connected with a krypton purification column (8) and a xenon purification column (10) through pipelines;
the outlet of the krypton purification column (8) is connected with a pure krypton collector (12) through a pipeline; the pure krypton collector (12) is connected to a connecting pipeline of the dissolver (2) and the gas storage tank (17) through a pipeline, and is connected with the krypton product dispensing bottle (13) through a pipeline;
the outlet of the xenon purification column (10) is connected with a pure xenon collector (15) through a pipeline; and the pure xenon collector (15) is connected to a connecting pipeline of the dissolver (2) and the gas storage tank (17) through a pipeline, and is connected with the xenon product dispensing bottle (16) through a pipeline.
2. Extraction from dissolved irradiated uranium target tail gas according to claim 1133Xe、135Xe、85The device for Kr is characterized in that a valve is arranged on a connecting pipeline between the gas drum bottle (1) and the dissolver (2); valves are arranged at the outlet of the dissolver (2) and the inlet of the gas storage tank (17) of a connecting pipeline of the dissolver (2) and the gas storage tank (17);
valves are arranged on the inlet and outlet pipelines of the low-temperature absorption purification column (3); a valve is arranged between the inlet and the outlet of the low-temperature absorption purification column (3);
valves are arranged on inlet and outlet pipelines of the xenon krypton separation column (5); a valve is arranged between the inlet and the outlet of the xenon-krypton separation column (5);
valves are arranged on the connecting pipelines of the outlet of the xenon-krypton separation column (5), the krypton purification column (8) and the xenon purification column (10);
a valve is arranged on a connecting pipeline between the krypton purification column (8) and the pure krypton collector (12); a valve is arranged on an outlet pipeline of the pure krypton collector (12);
a valve is arranged on a connecting pipeline of the xenon purification column (10) and the pure xenon collector (15); a valve is arranged on an outlet pipeline of the pure xenon collector (15);
and a valve is arranged on an exhaust pipeline of the air storage tank (17).
3. Extraction from dissolved irradiated uranium target tail gas according to claim 1133Xe、135Xe、85The device for Kr is characterized in that the low-temperature absorption purification column (3) is filled with an adsorbent; wherein the adsorbent is molecular sieve or active carbon.
4. Extraction from dissolved irradiated uranium target tail gas according to claim 1133Xe、135Xe、85-Kr device, characterized in that the low temperature absorption purification column (3) and the xenon krypton separation column (5) are in a cold trap; wherein the cold trap is filled with a refrigerant.
5. Extraction from dissolved irradiated uranium target tail gas according to claim 1133Xe、135Xe、85The Kr device is characterized in that the low-temperature absorption purification column (3) is a U-shaped tube, a convoluted tube or a needle-shaped tube.
6. Extraction from dissolved irradiated uranium target tail gas according to claim 1133Xe、135Xe、85Kr's device, characterized in that the low temperature absorption purification column (3) and cold trap (4) are in an all metal-tight environment.
7. Extraction from dissolved irradiated uranium target tail gas according to claim 1133Xe、135Xe、85The Kr plant is characterized in that the number of the low-temperature absorption purification columns (3) is more than or equal to 1.
8. Extraction from dissolved irradiated uranium target tail gas according to claim 1133Xe、135Xe、85The Kr device is characterized in that heaters are arranged outside the Kr purification column (8) and the Xe purification column (10).
9. Extraction from dissolved irradiated uranium target tail gas according to claim 1133Xe、135Xe、85The Kr device is characterized in that pressure gauges are arranged on the gas blowing cylinder (1), the dissolver (2) and the gas storage tank (17).
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