JP2016017934A - ON-DEMAND MANUFACTURING METHOD OF MEDICAL TECHNETIUM 99m AND SYSTEM THEREOF - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method and device ofTc capable of efficiently manufacturing the same while meeting on-demand requirement of customers at a low cost by sufficiently reflecting merits which can produceMo at 50 times more efficiently than a nuclear reactor radiation to manufacturing ofTc which is a raw material for an injection.SOLUTION: By constituting a tandem lineage of aMo solution tank and aTc extraction device and extractingTc fromMo of individualTc extraction devices of a plurality ofTc extraction devices connected to theMo solution tank independently while shifting time, aTc solution is continuously extracted as whole of a plurality of connectedTc extraction devices and on-demand extraction of theTc solution can be formed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an on-demand manufacturing method and system for medical technetium 99m.

Patent Document 1, a ^{100 Mo} raw material target was irradiated with fast neutrons from an accelerator neutron source, by absorption of a single neutron emitting two neutrons (n, 2n) to cause the reaction, ⁹⁹ Mo Is described.

Patent Document 2 describes that high-purity molybdenum sintered body is irradiated in a nuclear reactor to produce high density (n, γ) ⁹⁹ Mo.

Patent Document 3 describes that ⁹⁹ Tc and ^99m Tc in a high-concentration Mo solution are removed and purification treatment is performed.

Patent Document 4 describes a method for concentration and elution recovery of radioactive technetium by forming high-concentration ⁹⁹ Mo containing radionuclide ⁹⁹ Mo and ^99m Tc.

  Patent Document 5 describes an accelerator neutron source that has a plate-like metal target irradiated with a charged particle beam and a cooling water channel inside, and generates neutrons by irradiating the metal target with the charged particle beam. Has been.

  Patent Document 6 describes a radionuclide generation device for PET.

Patent Document 7 describes the relationship between neutron energy and reaction cross section, generation of radionuclide ⁹⁹ Mo by irradiation with fast neutrons from an accelerator, and separation of ^99m Tc by milking. Yes.

Non-Patent Document 1 describes that ⁹⁹ Mo / ^99m Tc is produced using ¹⁰⁰ Mo (γ, n) ⁹⁸ Mo.

As shown in the above-mentioned literature, it is known that radionuclide ⁹⁹ Mo is generated by inserting metal molybdenum or a molybdenum compound into a nuclear reactor and irradiating with neutrons. Moreover, ⁹⁸ Mo (n, γ) ⁹⁹ Mo reaction is generated by absorbing neutrons in ⁹⁸ Mo nuclei existing in natural isotope molybdenum at an isotopic ratio of 24.1%, thereby generating radionuclide ⁹⁹ Mo. It is known.

JP 2010-223937 A JP 2010-175409 A JP 2013-134063 A Japanese Patent No. 5427483 JP 2006-196353 A JP 2001-83297 A Japanese Patent Application Laid-Open No. 2010-223937

Atomic Energy Society of Japan "2014 Spring Annual Meeting" (March 26-28, 2014) 96 pages

As shown in the above-mentioned literature, a ⁹⁸ Mo (n, γ) ⁹⁹ Mo reaction is generated to produce radionuclide ⁹⁹ Mo pellet manufacturing technology, Mo pellet neutron irradiation technology, neutron irradiation Mo pellet dissolution and purification technology, and natural isotope Mo. ^-98 Mo (n, γ) ^99m Tc extraction technology from ⁹⁹ Mo is known.

By controlling the neutron energy within an appropriate range (0.01 to 40 keV), the unique neutron resonance absorption characteristics of ⁹⁸ Mo can be used, and the amount of ⁹⁹ Mo produced can be dramatically improved. In the case of reactor irradiation, it is difficult to freely control the neutron energy in order to keep the reactor critical, and ⁹⁹ Mo is generated using thermal neutrons (0.025 eV). On the other hand, in the case of accelerator neutron source irradiation, since neutron energy can be freely controlled, ⁹⁹ Mo can be generated using resonant neutrons (0.01 to 40 keV). By using a unique neutron resonance absorption characteristics of ^{98 Mo, 98 Mo (n,} γ) 99 Mo reaction cross section is increased 50 times compared to thermal neutrons. This means that the accelerator neutron source irradiation can use the unique neutron resonance absorption characteristics of ⁹⁸ Mo, and ⁹⁹ Mo can be generated 50 times more efficiently than the reactor irradiation. In the conventional technology, since it is not considered as a system that supports diagnostic on-demand, the advantage that ⁹⁹ Mo can be generated 50 times more efficiently than reactor irradiation is the raw material for the diagnostic ^99m It cannot be said that it is sufficiently reflected in the production of Tc, and no proposal for efficient production of ^99m Tc corresponding to the on-demand diagnostic agent has been made.

In view of this point, the present invention sufficiently reflects the merit that ⁹⁹ Mo can be generated 50 times more efficiently than reactor irradiation by using accelerator neutron source irradiation in the production of ^99m Tc as a raw material for diagnostic agents, For example, using a natural isotope ratio raw material Mo as a typical example, we propose a method for producing technetium 99m for medical use that is inexpensive and suitable for customer's diagnostic agent on-demand requirements, and that implements the method. The purpose is to do.

The present invention, raw Mo target, is a comprise pellets formed the ^{98 Mo,} to comprise pellets formed the ^{98 Mo,} an accelerator neutron source neutron energy is controlled to be within the neutron resonance absorption band Is irradiated under the condition that the neutron activation cross section by the irradiation increases, ^99m Tc parent nuclide ⁹⁹ Mo is generated, and stored in ⁹⁹ Mo solution storage means,
The ^{99 Mo} solution plurality of ^{99m Tc} extraction device is connected to the storage means is configured tandem system, the technetium 99m is extracted with a set time difference for each individual ^{99m Tc} extraction apparatus of a tandem system, a plurality of ^99m There is provided a method for producing technetium 99m for medical use, characterized in that the entire apparatus is extracted in response to on-demand diagnostics by Tc extraction.

The present invention relates to a method for producing technetium 99m for medical use, which comprises irradiating a natural isotope ratio raw material Mo target containing ⁹⁸ Mo as a target nucleus with neutrons from an accelerator neutron source to generate ^99m Tc parent nuclide ⁹⁹ Mo. In
1. The natural isotope ratio raw material Mo target is a pellet formed containing ⁹⁸ Mo,
2. A pellet formed containing ⁹⁸ Mo is irradiated with neutrons from an accelerator neutron source whose neutron energy is controlled to be within the neutron resonance absorption band of ⁹⁸ Mo, thereby producing ^99m Tc parent nuclide ⁹⁹ Mo. ,
3. Dissolve the irradiated pellets, purify the produced parent nuclide ⁹⁹ Mo,
4). ^{Comprising the} step of extracting ^99m Tc from the purified parent nuclide ⁹⁹ Mo;
Natural isotopic ratio material Mo target, rather than concentrating Mo isotope, is a pellet formed contains ^{98 Mo} of natural isotopic ratio, the pellets formed contains ^{98 Mo} of natural isotopic ratio, neutron Irradiating neutrons from an accelerator neutron source whose energy is controlled to be in the neutron resonance absorption band under the condition that the neutron activation cross section by the irradiation increases, to generate ^99m Tc parent nuclide ⁹⁹ Mo, ⁹⁹ Mo solution storage means,
The ^{99 Mo} solution plurality of ^{99m Tc} extraction device is connected to the storage means is configured tandem system, the technetium 99m is extracted with a set time difference for each individual ^{99m Tc} extraction apparatus of a tandem system, a plurality of ^99m There is provided a method for producing technetium 99m for medical use, characterized in that the entire apparatus is extracted in response to on-demand diagnostics by Tc extraction.

The present invention, in the above-described method for manufacturing a medical technetium 99m, tandem tandem system is provided with ^{99m Tc} extracting apparatus of ^{99m Tc} extraction system of the plurality connected tandem configuration ^{99 Mo} solution storage means is acquired There is provided a method for producing medical technetium 99m, characterized in that medical technetium 99m is extracted based on independent ^99m Tc extraction instructions for each system.

The present invention, in the above-described method for manufacturing a medical technetium ^99m, 99 Mo solution means comprises a plurality of ⁹⁹ Mo solution tank, each ^99m Tc extraction device is connected to a plurality of ⁹⁹ Mo solution tank, separate technetium 99m A method for producing technetium 99m for medical use is provided, in which extraction is performed with a time difference set for each ^99m Tc extraction apparatus, and the plurality of ^99m Tc extractions are performed in response to on-demand diagnostics as the entire apparatus. .

The present invention relates to the above-described method of manufacturing technetium 99m for medical use, wherein ⁹⁹ Mo solution means is a plurality of ⁹⁹ Mo solutions arranged in close proximity to the first pellet irradiated with neutrons from the accelerator neutron source. A tank, a second pellet is arranged in close proximity to the ⁹⁹ Mo solution tank, the second pellet is replaced with the first pellet, and a ^99m Tc extraction device is connected to each of a plurality of ⁹⁹ Mo solution tanks The technetium 99m is extracted with a time difference set for each individual ^99m Tc extraction device, and extracted according to the on-demand diagnostic agent as a whole device by a plurality of ^99m Tc extractions. A manufacturing method is provided.

The present invention, raw Mo target, is a comprise pellets formed the ^{98 Mo,} to comprise pellets formed the ^{98 Mo,} an accelerator neutron source neutron energy is controlled to be within the neutron resonance absorption band Is irradiated under the conditions that increase the neutron activation cross section by the irradiation, ^99m Tc parent nuclide ⁹⁹ Mo is generated, stored in ⁹⁹ Mo solution means,
The ^{99 Mo} solution plurality of ^{99m Tc} extraction device is connected to the storage means is configured tandem system, technetium 99m is extracted with a set time difference for each individual ^{99m Tc} extraction apparatus of a tandem system, a plurality of ^99m An apparatus for producing technetium 99m for medical use, characterized in that the entire apparatus is extracted in response to on-demand diagnosis by Tc extraction.

The present invention relates to an apparatus for producing technetium 99m for medical use, which comprises irradiating a natural isotope ratio raw material Mo target containing ⁹⁸ Mo as a target nucleus with neutrons from an accelerator neutron source to generate ^99m Tc parent nuclide ⁹⁹ Mo. In
1. The natural isotope ratio raw material Mo target is a pellet formed containing ⁹⁸ Mo,
2. A pellet formed containing ⁹⁸ Mo is irradiated with neutrons from an accelerator neutron source whose neutron energy is controlled to be within the neutron resonance absorption band of ⁹⁸ Mo, thereby producing ^99m Tc parent nuclide ⁹⁹ Mo. ,
3. Dissolve the irradiated pellets, purify the produced parent nuclide ⁹⁹ Mo,
4). ^{Comprising the} step of extracting ^99m Tc from the purified parent nuclide ⁹⁹ Mo;
Natural isotopic ratio material Mo target, rather than concentrating Mo isotope, is a natural isotopic ratio ^{98 Mo} a comprise formed the MoO ₃ pellets, MoO ₃ formed to include a ^{98 Mo} natural isotopic ratio The pellet is irradiated with neutrons from an accelerator neutron source whose neutron energy is controlled to be in the neutron resonance absorption band under the condition that the neutron activation cross section by the irradiation increases, and the ^99m Tc parent nuclide ⁹⁹ Mo Is produced and stored in ⁹⁹ Mo solution means,
The ^{99 Mo} solution plurality of ^{99m Tc} extraction device is connected to the storage means is configured tandem system, technetium 99m is extracted with a set time difference for each individual ^{99m Tc} extraction apparatus of a tandem system, a plurality of ^99m An apparatus for producing technetium 99m for medical use, characterized in that the entire apparatus is extracted in response to on-demand diagnosis by Tc extraction.

The present invention is a manufacturing apparatus of the above-described medical technetium 99m, tandem tandem system is provided with ^{99m Tc} extracting apparatus of ^{99m Tc} extraction system of the plurality connected tandem configuration ^{99 Mo} solution storage means is acquired Provided is a medical technetium 99m manufacturing apparatus in which medical technetium 99m is extracted based on independent ^99m Tc extraction instructions for each system.

The present invention is a manufacturing apparatus of the above-described medical technetium ^99m, 99 Mo solution means comprises a plurality of ⁹⁹ Mo solution tank, each ^99m Tc extraction device is connected to a plurality of ⁹⁹ Mo solution tank, technetium 99m is individually A ^99m Tc extraction device is extracted with a time difference set for each of the ^99m Tc extraction devices, and a plurality of ^99m Tc extraction devices are extracted corresponding to the diagnostic agent on demand as a whole device. To do.

The present invention is the above-described apparatus for producing technetium 99m for medical use, wherein the ⁹⁹ Mo solution means is a plurality of ⁹⁹ Mo solutions arranged in close proximity to the first pellet irradiated with neutrons from the accelerator neutron source. A tank, a second pellet is arranged in close proximity to the ⁹⁹ Mo solution tank, the second pellet is replaced with the first pellet, and a ^99m Tc extraction device is connected to each of a plurality of ⁹⁹ Mo solution tanks Technetium 99m is extracted with a time difference set for each individual ^99m Tc extraction device, and extracted as a whole by the plurality of ^99m Tc extractions corresponding to the diagnostic agent on-demand. 99m manufacturing equipment is provided.

The present invention is a neutron irradiated apparatus that is used in the above-described medical technetium 99m manufacturing apparatus and is irradiated with neutrons from a neutron irradiation apparatus, and is a first pellet irradiated with neutrons from an accelerator neutron source A plurality of ⁹⁹ Mo solution tanks arranged in close proximity to each other are disposed, a second pellet is disposed in close proximity to the ⁹⁹ Mo solution tank, and graphite is disposed in close proximity to the second pellets. Arranged, the second pellet is replaced with the first pellet, and a plurality of ⁹⁹ Mo solution tanks are neutron-irradiated to mitigate ⁹⁹ Mo attenuation, and a ⁹⁹ Mo solution is extracted from each of the plurality of ⁹⁹ Mo solution tanks. The ⁹⁹ Mo solution tank and the first and second pellets act as a neutron shielding body.

The present invention provides a neutron irradiated apparatus characterized in that a ⁹⁹ Mo solution tank is disposed so as to surround the first pellet described above from three directions.

According to the present ^invention, 99 Mo solution tank ^99m Tc extraction device is a plurality of connected, by technetium 99m is extracted with a set time difference for each individual ^99m Tc extractor, multiple connected ^99m Tc The extraction device as a whole can be extracted in response to on-demand medical diagnostics. By using the accelerator neutron source radiation, 50-fold efficiently than in the case of reactor irradiation can produce a parent nuclide ^{99 Mo} of ^{99m Tc,} on-demand production of ^{99m Tc} to the benefits of this as a raw material for the diagnostic The production method and / or device (or system) of medical technetium 99m is proposed, which is suitable for the on-demand demand for diagnostic reagents that are inexpensive and promptly provided by customers, and that enables efficient production and formulation. The

The figure which shows one form of the Example of this invention. FIG. 2 shows an apparatus and method representing a form for on-demand production of high purity ^99m Tc solution. It illustrates one example of the irradiation MoO ₃ pellets. The figure which shows the other example of an irradiation target. The figure which shows one example of the accelerator neutron source for Mo irradiation. MoO ₃ illustrates one example of a pellet irradiation system. Perspective view showing the arrangement of one example of MoO ₃ pellets irradiation system. It shows a neutron flux energy distribution in one example of MoO ₃ pellets irradiation system. The figure which shows the neutron flux energy distribution in a nuclear reactor (light water reactor) core. MoO ₃ shows another example of the pellet irradiation system. ^The figure which shows the neutron absorption cross section of ⁹⁸ Mo. The figure which shows the example of a neutron irradiation Mo pellet melt | dissolution apparatus. ^The figure which shows the example of ^99m Tc extraction apparatus. The figure which shows the manufacturing step of a highly purified ^99m Tc solution by the step of S1-S7. The figure which shows the modification of the manufacturing apparatus of medical technetium 99m. The figure which shows the concept of the 2nd Example of this invention. The figure which shows the detailed form of the concept shown in FIG. The figure which compared this invention Example with the comparative example.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing steps of an embodiment of the present invention. FIG. 2 corresponds to FIG. 1 and shows a method and apparatus representing a form for on-demand production of high purity ^99m Tc solution.

In FIG. 1, the present embodiment is, for example, as a typical example: 1. Manufacture of natural isotope ratio raw material Mo target containing ⁹⁸ Mo pellet (MoO ₃ pellet manufacture)
2. ^The pellet formed to contain ⁹⁸ Mo is irradiated with neutrons from an accelerator neutron source whose neutron energy is controlled to be within the neutron resonance absorption band of ⁹⁸ Mo to generate ^99m Tc parent nuclide ⁹⁹ Mo ( Accelerator irradiation ⁹⁹ Mo production)
3. Dissolve the irradiated pellets and purify the produced parent nuclide ⁹⁹ Mo (neutron irradiation Mo pellet dissolution / purification)
4). Extract ^99m Tc from the purified parent nuclide ⁹⁹ Mo ( ^99m Tc extraction and recovery)
Comprising the steps of:

Through these steps, on-demand production of each high-purity ^99m Tc solution is possible in the tandem system described below, and ^99m Tc formulation is made and shipped on demand to hospitals or nuclear medicine centers. .

Here corresponding to a diagnostic on demand and as possible to extract supplied corresponding to the arbitrary orders from main orders such as hospitals or nuclear medicine center, as in the prior art, a diagnostic agent ^99m Tc This means that the production time of the solution is not determined by the convenience of the manufacturer, but is determined according to the convenience of the orderer and shipped.

In the MoO ₃ pellet production step, natural isotope ratio MoO ₃ high-purity powder is used as the raw material Mo, and MoO ₃ pellets that are irradiation targets are produced by a plasma sintering method.

FIG. 3 is a diagram illustrating an apparatus and method representing a form for on-demand production of the high purity ^99m Tc solution shown in FIG. In order to facilitate understanding before describing the configuration shown in FIG. 2, devices related to the present embodiment will be described first.

FIG. 3 shows one example of a MoO ₃ pellet for irradiation. Irradiated MoO ₃ pellets are typically shaped, for example, to be 10 inches in diameter (25.4 cm) by 1 cm thick, with an isotope ratio of ⁹⁸ Mo in the pellet of 24.1%. FIG. 3 shows an integral pellet.

  The shape of the pellet is not limited to this example, and may be a system in which small diameter types are arranged, or the thickness and diameter may be appropriately changed.

  FIG. 4 shows another example of pellets that are irradiation targets. In this example, the pellet shape as the irradiation target is a small-diameter type pellet, and a large number of independent small-diameter type pellets are arranged and arranged, and when the pellets shown in FIG. Be the same.

In FIG. 1, an accelerator neutron source for natural Mo irradiation is used for accelerator irradiation ⁹⁹ Mo production, and thermal neutron irradiation is performed on MoO ₃ pellets. In this thermal neutron irradiation, the neutron from the accelerator neutron source reaches the ⁹⁸ Mo nucleus after being decelerated by a moderator composed of a nucleus having a large mass number, such as lead. The peak energy of neutrons emitted by the accelerator for natural Mo irradiation is about 1.9 MeV, and when a moderator with a small moderating ability is used, the natural Mo periphery has a range of 1.9 MeV to 0.025 eV (thermal neutron). A neutron flux having a flat energy distribution is formed. Therefore, the ⁹⁸ Mo (n, γ) ⁹⁹ Mo reaction can be generated by effectively utilizing the resonance absorption band of ⁹⁸ Mo nuclei. The ⁹⁸ Mo (n, γ) ⁹⁹ Mo reaction cross section for a neutron flux having a flat energy distribution in the range of 1.9 MeV to 0.025 eV is 6.5 burns. On the other hand, the ⁹⁸ Mo (n, γ) ⁹⁹ Mo reaction cross section for a neutron flux having a 0.025 eV monochromatic energy distribution is 0.13 burns. By irradiating natural Mo with neutrons from the accelerator neutron source through a moderator with a small decelerating ability, the reaction probability is 6.5 ÷ 0.13 = 50 compared to reactor irradiation (thermal neutron irradiation). Will be doubled.

FIG. 5 is a diagram showing one example of an accelerator neutron source 180 for Mo irradiation. The accelerator neutron source 180 for Mo irradiation includes a deuteron ion source (charged particle beam source) 188 that emits a deuteron ion beam 186, an acceleration tube 182 that accelerates the deuteron ion beam 186 to 2880 keV, and a deuteron ion beam after acceleration. It is comprised from the beryllium target 183 with which 186 collides, and the vacuum vessel 199. When the deuteron beam 186 accelerated to 2880 keV collides with the beryllium target 183, neutrons are emitted by the ⁹ Be (d, n) ¹⁰ B reaction. The emitted neutron is irradiated to the MoO ₃ pellet through the moderator in the irradiation system 190. Since the deuteron beam 186 hits the beryllium target 183 and stops, all of its kinetic energy is converted into thermal energy in the beryllium target 183. A cooling device 184 is provided to remove thermal energy from the beryllium target 183. The cooling device 184 is filled with light water and has a function of suppressing the temperature rise of the beryllium target 183 by constantly circulating the light water.

FIG. 5A shows a configuration example of the irradiation system 190. The irradiation system 190 includes a MoO ₃ pellet 185, a neutron moderator 181, and a neutron shielding material 197. Neutrons emitted from the beryllium target 183 are diffused through the neutron moderator 181 and irradiated to the MoO ₃ pellet 185. When lead is used for the neutron moderator 181, the moderation capacity is small, and therefore, a neutron flux having the energy distribution shown in FIG. 5C is formed in the vicinity of the center of the MoO ₃ pellet 185.

FIG. 5B is a perspective view showing a mounting structure example of the MoO ₃ pellet 185. Neutrons are generated from the beryllium target 183. It is necessary to install the MoO ₃ pellet 185 as close as possible to the beryllium target 183 that is the neutron generation source. In the example shown in FIG. 5B, the MoO ₃ pellet 185 is in close contact with the beryllium target cooling device 184, and the MoO ₃ pellet. The center of 185 is installed so as to overlap the extended line of the central axis of the deuteron beam 186. By taking such an arrangement, the neutron flux intensity inside the beryllium target 183 can be maximized. The neutron moderator 181 is made of metallic lead and is disposed so as to wrap the beryllium target 183, the beryllium target cooling device 184, and the MoO ₃ pellet 185. Although not shown in FIG. 5B, a neutron shielding material 197 is installed so as to further enclose the neutron moderator 181.

FIG. 5C is a neutron flux energy spectrum near the center of the MoO ₃ pellet 185. From FIG. 5C, it can be seen that the energy distribution of the neutron flux becomes substantially flat in the region from 0.025 eV (thermal neutron region) to 1 MeV (neutron emission energy region of the accelerator neutron source 180 for Mo irradiation).

FIG. 5 (D) is a diagram showing the energy distribution of the neutron flux in the nuclear reactor (light water reactor) core. In a nuclear reactor (light water reactor), fast neutrons generated by fission are decelerated with light water with a large decelerating ability. This is because criticality cannot be continued unless neutrons are heated with a small number of collisions and a certain fission number is maintained. Therefore, in terms of the energy distribution, the ratio of neutrons existing in the energy range of 0.01 to 40 keV is overwhelmingly smaller than the neutron flux by the Mo irradiation accelerator neutron source 180 shown in FIG. I understand. Even in a nuclear reactor, a moderator with a small moderating ability can be applied to increase the ratio of the number of neutrons in the decelerated neutron region. In this case, the resonance absorption probability of ²³⁵ U increases and the criticality cannot be maintained. For this reason, the nuclear reactor (light water reactor) makes it impossible to freely control the neutron flux energy distribution. On the contrary, since it is not necessary to maintain the criticality in the accelerator neutron source, a moderator having an arbitrary moderating ability can be freely selected. For this reason, the accelerator neutron source can freely control the neutron flux energy distribution.

In the irradiation system of FIG. 5 (A), since the ratio of neutrons existing in the energy region of 0.01 to 40 keV can be increased, ⁹⁹ Mo of ⁹⁹ Mo which effectively uses the resonance absorption peak of the ⁹⁸ Mo (n, γ) ⁹⁹ Mo reaction Generation is possible. With such a configuration, the utilization rate of neutrons in the radionuclide generation region is improved.

In the Mo irradiation accelerator neutron source 180 shown in FIG. 5, when the current value of the deuteron ion beam 186 is about 340 mA, the neutron source intensity is 8.4 × 10 ¹⁴ atoms / second. In this neutron source intensity, the neutron flux intensity in the vicinity of the center of the MoO ₃ pellet 185 is 8.8 × 10 ¹² pieces / cm ² / sec, and this intensity is the neutron flux intensity inside the BWR (boiling water light water reactor) core. The value is equal to or greater than. That is, in the irradiation system shown in FIG. 5 (B), the amount of ⁹⁹ Mo produced in the MoO ₃ pellet 185 can be increased by about 50 times compared to the time of reactor irradiation.

FIG. 6 is a diagram showing the neutron absorption cross section of ⁹⁸ Mo.

It can be seen from FIG. 6 that a ⁹⁸ Mo neutron resonance absorption peak exists in the region where the neutron energy is 0.01 to 40 keV. Therefore, the ⁹⁸ Mo cross section for the neutron spectrum shown in FIG. 5C is almost equal to 6.5 so-called resonance integral value (Resonance Integral). Compared to the thermal neutron absorption cross section of 0.13 barn in the case of thermal neutron irradiation in a nuclear reactor, it can be seen that the neutron absorption cross section is significantly increased by the effect of the resonance absorption peak. That is, when utilizing the unique neutron resonance absorption characteristic of ⁹⁸ Mo, the natural isotope ratio is not a concentrated Mo isotope, even if irradiation is performed with a neutron flux intensity of about 10 ¹² to 10 ¹³ / n / cm ² / sec. It becomes possible to produce sufficient amount and specific activity of ⁹⁹ Mo in the MoO ₃ pellet 185 formed of Mo.

In FIG. 6, the ¹⁰⁰ Mo (n, 2n) ⁹⁹ Mo reaction cross-sectional area is shown. Although the reaction cross section increases from around 10 MeV, ¹⁰⁰ Mo has a low isotope ratio of 9.63%, and a sufficient amount of ⁹⁹ Mo can be obtained unless the step of increasing the isotope ratio by the enrichment process is performed. Can not. Therefore, there is a disadvantage that the cost of the Mo raw material becomes expensive.

FIG. 5E is a diagram showing a modification of the irradiation system 190. A configuration in which a plurality of MoO ₃ pellets are irradiated simultaneously may be employed. In the example shown in FIG. 5A, a total of about 2500 Curies of ⁹⁹ Mo can be generated in the MoO ₃ pellet 185 by neutron irradiation for 100 hours. In the example shown in FIG. 5E, in the first irradiation, ⁹⁹ Mo generated in the MoO ₃ pellet 185 becomes 2500 Curie after 100 hours irradiation, which is the same value as the configuration of FIG. However, in FIG. 5 (E), a total of about 1000 Curie of ⁹⁹ Mo is also generated in the MoO ₃ pellet 185A during the 100-hour irradiation. In the next irradiation, the MoO ₃ pellet 185A is loaded at the position of the MoO ₃ pellet 185, and the unirradiated MoO ₃ pellet is newly loaded as the MoO ₃ pellet 185A. If the waiting time from the first irradiation to the next irradiation is 48 hours, the irradiation is started from the state in which about 660 Curie of ⁹⁹ Mo is already contained in the MoO ₃ pellet 185 in the next irradiation.

In the configuration of FIG. 5 (E), the amount of ⁹⁹ Mo that can be generated in the MoO ₃ pellet 185 after 100 hours of irradiation after the second irradiation is about 3100 Curie in total, and ⁹⁹ Mo generation efficiency can be further improved. Become.

Returning to FIG. 1, in the neutron irradiation Mo pellet dissolution / purification step, the neutron irradiation Mo ( ⁹⁹ Mo) pellet is dissolved with NaOH solution and purified with a chelate resin to produce a purified Mo ( ⁹⁹ Mo) solution.

FIG. 7 is a diagram showing an example of a neutron irradiation Mo pellet melting apparatus. Irradiated Mo pellet pieces 188 are put into a neutron irradiation Mo pellet melting apparatus (irradiated MoO ₃ dissolution tank 187). In such a state, a NaOH solution 186 as a dissolving agent is introduced. Mo pellet pieces irradiated with neutrons with NaOH are gradually dissolved. A Mo ( ⁹⁹ Mo) solution 189 is produced. Further, the chelate resin is purified.

The purified Mo ( ⁹⁹ Mo) solution is carried into a Mo tank described later of ^99m Tc extraction (manufacturing) means.

Returning to FIG. 1, in the ^99m Tc extraction and recovery step, the purified Mo ( ⁹⁹ Mo) solution is passed through the activated carbon column, and ^99m Tc adsorption recovery is performed. Further, washing and NaOH flow are performed, ^99m Tc elution recovery is performed, transferred to an alumina column, and recovery ^99m Tc purification is performed.

FIG. 8 is a diagram illustrating an example of the ^99m Tc extraction and production apparatus 51. FIG. 9 is a diagram showing steps for producing a high-purity ^99m Tc solution in steps S1 to S7.

8 and 9, the ^99m Tc extraction and production apparatus 51 is installed in a hot cell that shields radiation emitted from ⁹⁹ Mo and ^99m Tc. ^{The 99m} Tc extraction and production apparatus 51 includes a Mo container (1) 52, a Mo container (2) 53, and a control tank. A plurality of Mo containers may be provided. The Mo container (1) 52 and the Mo container (2) 55 are supplied with a Na ₂ ⁹⁹ MoO ₄ solution generated by neutron irradiation to generate ⁹⁹ Mo and dissolve the contained MoO ₃ with an alkali (NaOH) solution. The That is, the Mo solution containing the radionuclide ⁹⁹ Mo as a radiopharmaceutical raw material is supplied to the Mo container (1) 52 and the Mo container (2) 53. ^{When 99} MoO ₃ is dissolved in an alkaline solution, a pH neutral Na ₂ ⁹⁹ MoO ₄ solution is formed as shown in the figure.

At the time of production, the Mo solution containing radioactive ⁹⁹ Mo is, for example, a high concentration Mo solution containing 500 g of Mo in 2 L. Hereinafter, this solution is referred to as a high concentration Mo solution. Here, the high concentration is, for example, a concentration at which a high concentration Mo solution containing 500 g of Mo in 2 L described above is required to obtain a necessary amount of ^99m Tc of about 500 Ci at a time.

  Pipings 57 and 58 having three-way valves 55 and 56 are respectively provided at the bottoms of the Mo container (1) 52 and the Mo container (2) 53, and the Mo container (1) 52 and the Mo container (2) 53 are Three-way valves 55 and 56 and pipes 57 and 58 are connected to the bottom of the control tank 54 via other pipes 59 and 60. A three-way valve 63 is provided at the end of the pipes 57 and 58. The control tank 54 has a function as a liquid level adjustment mechanism. The bottom of the control tank 54 is further connected to one end (upper surface in the figure) of the Tc concentration purification / recovery system 66 via a pipe 64 and a three-way valve 65 provided in the pipe 64. As will be described later, the Tc concentration purification / recovery system 66 includes an adsorption column containing activated carbon.

The other end (lower end in the figure) of the Tc concentration purification system 66 is provided with a pipe 67 and a three-way valve 68 provided on the pipe 67 and connected to a three-way valve 63 provided at the end of the pipe 57 and the pipe 58. The In Mo vessel (1) 52 and Mo vessel (2) 53, a high concentration Mo solution ^99m Tc is generated, the daughter nuclide of ^99m Mo in a high concentration Mo solution containing radionuclide ⁹⁹ Mo and ^99m Tc are formed Is done. A new high-concentration Mo solution containing ⁹⁹ Mo is alternately supplied to, for example, every Mo container (1) 52 and Mo container (2) 53 every two weeks.

Technetium 99 ( ^99m Tc), which emits weak energy gamma rays (radiation), is used for medical diagnosis such as SPECT, but its half-life is 6 hours, so its radioactivity is reduced to 1/16 of a day. Will decrease. It holds a ⁹⁹ Mo, which is the parent nuclide of ^99m Tc in order to compensate for this, to separate and use the ^99m Tc born causing the beta-minus decay. A method for obtaining a daughter nuclide using the radiation equilibrium relationship between the parent nuclide and the daughter nuclide is called milking.

Here, the method for obtaining the daughter nuclide by using the radiation equilibrium relationship between the parent nuclide and the daughter nuclide is called milking. Moreover, performing this milking is called a milking process, and the solution containing a daughter nuclide is called a milking solution. Thus, where a high concentration Mo solution containing ^{99 Mo,} as described above, is that a solution containing ^{99 Mo} for obtaining ^{99m Tc} required amount by utilizing radiation equilibrium.

The high-concentration ⁹⁹ Mo solution is introduced into the Tc concentration purification / recovery system 66 containing the activated carbon column from the lower part of the Tc concentration purification / recovery system 66 through the pipe 57, the pipe 58, the three-way valve 63, and the pipe 67. The Tc concentration purification / recovery system 66 includes an adsorption column, and activated carbon is incorporated in the adsorption column, so ^99m Tc is selected by passing a high concentration ⁹⁹ Mo solution containing a necessary amount of ^99m Tc through the activated carbon. Can be adsorbed. In this step, ^99m Tc is purified and concentrated. Here, the relationship between the ⁹⁹ Mo amount and the ^99m Tc amount with respect to the Mo amount (here, 500 g) in the high-concentration Mo solution is as follows.

⁹⁹ Mo half-life: 65.94 h, ^99m Tc half-life: 6.01 h
500 Ci ⁹⁹ Mo amount = 1.04 mg (1 / 500,000 for 500 g Mo)
500 Ci ^99m Tc amount = 0.095 mg (1/5 million for 500 g Mo)
^{In the case of 99} Mo 5 × 10 ⁴ Bq or less, 6 × 10 ⁻¹⁵ or less with respect to 500 g Mo
^{In the case of 99m} Tc 6 × 10 ⁴ Bq or less, 6 × 10 ⁻¹⁶ or less with respect to 500 g Mo. Thus, even when ^99m Tc is present in a very high concentration Mo solution, it can be adsorbed by activated carbon.

A large amount of Mo containing ⁹⁹ Mo that is not adsorbed by the Tc concentration purification / recovery system 66 passes through the three-way valve 65 and the pipe 64 to the control tank 54, and further to either the Mo container (1) 52 or the Mo container (2) 53. It will be returned. A ^99m Tc adsorption step is performed every day, and the Mo solution from which ^99m Tc has been recovered is returned to the original Mo container (either 52 or 53). After this step, ^99m Tc adsorbed and recovered by the Tc concentration purification recovery system 66 is transferred to a desorption step.

In this way, a high concentration Mo solution containing the radionuclide ⁹⁹ Mo is dissolved in the neutron-irradiated Mo compound (MoO ₃ ) directly in an alkaline solution to form a high concentration Mo solution containing ⁹⁹ Mo. A high concentration ⁹⁹ Mo solution stored in a plurality of Mo containers is alternately passed through an adsorption column containing the activated carbon, and Tc is adsorbed and concentrated. Do.

An external supply system 82 is connected to the three-way valve 68 via a pipe 80 and a three-way valve 81, and from this supply system 82, a cleaning liquid for desorption of ⁹⁹ Mo remaining in the Tc concentration purification / recovery system 66 (activated carbon column). And Tc eluate and the like are supplied, and these solutions are introduced into the Tc concentration purification collection system 66.

First, in the desorption process, ⁹⁹ Mo desorbent is introduced from the supply system 82, ⁹⁹ Mo is desorbed, and this solution is led to the cleaning waste liquid 82. Next, the ⁹⁹ Mo desorption process is stopped, and the process proceeds to a Tc desorption process in which Tc adsorbed on the activated carbon is desorbed.

The Tc concentration purification / recovery system 66 is connected to a liquidity adjustment system 75 via a three-way valve 65 and a pipe 73 and a three-way valve 74 provided thereon. The desorbed Tc is introduced into the liquid property adjusting system 75 together with the desorbing agent. In this liquid adjustment system, a liquid adjustment reagent 84 is added to adjust the liquidity. Further, the liquid adjustment reagent 84 is further connected to the secondary purification system 77 via the pipe 76 and further connected to the Tc recovery device 79 via the pipe 78. ^99m Tc Collected as eluate.

As shown in FIG. 8, this system is provided with ⁹⁹ Mo post-use waste liquid systems 80 and 81 and a cleaning waste liquid system 82, and each system is appropriately controlled by a control system 83.

As described above, a high-concentration Mo solution containing radionuclide ⁹⁹ Mo as a radiopharmaceutical raw material is formed, ^99m Tc which is a daughter nuclide of ⁹⁹ Mo is generated, and high concentration ⁹⁹ containing radionuclide ⁹⁹ Mo and ^99m Tc is formed. Forming a Mo solution;
Formed was the high concentration ⁹ Mo solution was passed through the adsorption column that incorporates activated carbon is selectively adsorb ^{99m Tc} of the high density ^{99 Mo} solution to the activated carbon and selectively adsorbing the ^{99m Tc} is derived recirculation system at a high concentration ⁹⁹ Mo after the ⁹⁹ Mo remaining in the activated carbon subjected to desorption removed by Mo desorbent, the desorption process of the ^99m Tc by desorbing agent ^99m Tc traces remaining on the activated carbon activated carbon Go and collect ^99m Tc,
Perform secondary purification to remove ⁹⁹ Mo slightly remaining in the recovered ^99m Tc by the alumina column method,
^99m Tc is adsorbed, extracted into the recirculation system, and recovered from the high concentration ⁹⁹ Mo solution, ^99m Tc is generated again to the radiation equilibrium state, and high concentration ⁹⁹ Mo containing radionuclides ⁹⁹ Mo and ^99m Tc is produced. the solution was again formed, the formed the high density ^{99 Mo} solution, thereby selectively adsorbing the ^{99m Tc} recirculation to in the high density ^{99 Mo} solution to the activated carbon passed through the adsorption column having a built-in active carbon A ^99m Tc highly concentrated and elution purified recovery method as a radiopharmaceutical raw material characterized by the above is formed.

^The method of extracting ^99m Tc is not limited to the method shown in FIG. 8, and may be a case where it is made by another method.

In this way, a high purity ^99m Tc solution is produced. The high-purity ^99m Tc solution produced in this step is used to extract and recover high-concentration and high-purity ^99m Tc using (n, γ) ⁹⁹ Mo having a low specific activity as a raw material. Similarly, in the case of accelerator neutron source irradiation, high concentration and high purity ^99m Tc can be extracted and recovered using (n, γ) ⁹⁹ Mo having a low specific activity as a raw material. The amount of high-concentration and high-purity ^99m Tc to be produced is not limited to the reactor irradiation capacity as in the prior art, but should be an arbitrarily large amount that is relatively free. Can do. Along with this, on-demand production corresponding to on-demand from many orderers such as hospitals or nuclear medicine centers becomes possible.

Returning to FIG. FIG. 2 shows an apparatus and method representing a configuration for on-demand production of high purity ^99m Tc solution. In correspondence with the configuration shown in FIG. 8, the Mo containers 52 and 53 shown in FIG. 8 correspond to the ⁹⁹ Mo solution tank 25, and the control tank 54 corresponds to the adjustment tank 24. ^{The 99m} Tc extraction device 26 includes a Tc concentration purification collection system 66 (activated carbon column).

In FIG. 2, the manufacturing apparatus 100 of the medical technetium 99m which is an Example of this invention is shown. Manufacturing apparatus 100 medical technetium-99m, MoO ₃ MoO ₃ pelletizer for pelletizing apparatus for manufacturing a parent nuclide ⁹⁹ Mo of ^99m Tc by accelerator irradiation ⁹⁹ Mo production, for neutron irradiation Mo pellets dissolved and purified dissolution of the parent nuclide ⁹⁹ Mo, composed purifier and ^99m Tc production apparatus. FIG. 2 shows the ^99m Tc manufacturing apparatus 26. Multiple ^99m Tc preparation apparatus 6 is cooperate in a plurality of ^99m Tc production apparatus 26.

In the MoO ₃ pellet manufacturing apparatus, a natural isotope ratio powder MoO ₃ raw material is used as a raw material Mo target. The natural isotope ratio powder MoO ₃ raw material contains ⁹⁸ Mo. ⁹⁸ Mo is contained in natural Mo at 24.1%, the absorption cross section of thermal neutrons is 0.13 barn, and the half life of the produced ⁹⁹ Mo is 65.94 h. A sintered MoO ₃ pellet containing ⁹⁸ Mo (hereinafter referred to as MoO ₃ pellet) is produced from the natural isotope ratio powder MoO ₃ raw material. Although the pellet shape may not be used, the pellet shape is suitable for the subsequent processing, and the MoO ₃ pellet will be described as an example.

Pellets containing parent nuclide ⁹⁹ Mo of the generated ^99m Tc is dissolved parent nuclide ⁹⁹ Mo in refining apparatus purification. That is, the neutron irradiated Mo pellet dissolving apparatus is used to dissolve the neutron irradiated Mo pellet, and the ⁹⁹ Mo refining apparatus is used to purify the dissolved ⁹⁹ Mo, thereby producing a purified ⁹⁹ Mo solution.

^{The 99m} Tc manufacturing apparatus 26 is a hot cell surrounded by the radiation shielding wall 11 on the outside, and the maintenance area 12 and the ^99m Tc extraction area 13 are partitioned by the partition wall 14 inside.

An internal hot cell surrounded by the internal shielding wall 15 is formed at the center of the hot cell, and the inside thereof is further divided into two by a partition wall 21, one area is a ⁹⁹ Mo filling area 22, and the other area is ⁹⁹ Mo. The solution holding area 23 is used. ^{The 99m} Tc extraction area 13 is arranged outside the ⁹⁹ Mo solution holding area 23. That is, the outer side is a plurality of ^99m Tc extraction areas 13. ^A power supply control device 44 is disposed in the lower chamber 43 formed below the ⁹⁹ Mo solution holding area 23, and various controls of the ^99m Tc extraction device 26 in the hot cell are performed.

^{In the 99} Mo solution holding area 23, an adjustment tank 24 and a plurality of ⁹⁹ Mo solution tanks 25 are arranged. In the figure, two ⁹⁹ Mo solution tanks 25 are arranged. Adjusting tank 24, and a plurality of ^{99 Mo} solution tank 25 is connected so as to be described later. The adjustment tank 24 and the plurality of ⁹⁹ Mo solution tanks 25 are sometimes collectively referred to as a ⁹⁹ Mo solution built-in tank.

^{In the 99m} Tc extraction area 13, a plurality of ^99m Tc extraction devices 26, that is, a ^99m Tc solution production device is arranged. In the figure, two ^99m Tc extraction devices 26 are described. Each ^99m Tc extraction device 26 is connected to a ⁹⁹ Mo solution tank 25. The solution after the ^99m Tc extraction may be returned to the adjustment tank 24 or may be collected as a waste liquid. The plurality of ^99m Tc extraction devices 26 include ^99m Tc transfer means 27 connected thereto, and an outer end thereof serves as a ^99m Tc recovery port 28. Each ⁹⁹ Mo solution tank 25 and the ^99m Tc extraction device 26 is a tandem system, the operation of each independently are possible.

  A door 31 is formed on the shielding wall 11 in the upper part of the figure, a door 32 is formed on the side of the figure, and a door 33 is formed on the inner shielding door 21. A door 34 is provided on the inner shielding wall 15.

The maintenance area ^12, the rail 35 for conveying the ^99m Tc extractor 26 be connected to the ^99m Tc extractor 26 is ^arranged, is possible to perform maintenance pull the ^99m Tc extractor 26 to maintenance area 12 I can do it.

The ⁹⁹ Mo solution generated by the dissolution and purification apparatus of the parent nuclide ⁹⁹ Mo is carried into the maintenance area 12. ⁹⁹ Mo solution carried into the maintenance area ^12, 99 Mo solution for replenishment filling of the tank 25 is carried 41 to ⁹⁹ Mo filling area 22, further either ⁹⁹ Mo solution tank of the plurality of ⁹⁹ Mo solution tank 25 25.

⁹⁹ Mo solution tank ⁹⁹ Mo solution filled in 25, under computer control, it is filled in any of ^99m Tc extractor 26.

According to this structure, the highly radioactive ⁹⁹ Mo solution tank 25, that is, the ⁹⁹ Mo solution built-in tank is disposed in the internal hot cell surrounded by the internal shielding wall 15, and the ^{99 m} Tc extraction device 26 having relatively weak radioactivity is provided. It is arranged in a hot cell surrounded by the radiation shielding wall 11 in the outer ^99m Tc extraction area 13.

In the present embodiment, the natural isotope ratio raw material Mo target is not a concentrated Mo isotope, but a pellet formed containing ⁹⁸ Mo having a natural isotope ratio, and is formed containing ⁹⁸ Mo having a natural isotope ratio. The pellets were irradiated under conditions where the neutron activation cross-section increased by neutron irradiation from an accelerator neutron source whose neutron energy was controlled to be within the neutron resonance absorption band of ⁹⁸ Mo, and the parent of ^99m Tc The nuclide ⁹⁹ Mo is generated and stored in the ⁹⁹ Mo solution tank. ^{Although two 99} Mo solution tanks 25 are provided as a pair in the figure, two or more ⁹⁹ Mo solution tanks may be provided. ^A plurality of ⁹⁹ Mo solution built-in tanks may be provided as a set. The arrangement of the ⁹⁹ Mo solution tank 25 corresponds to the arrangement of the ^99m Tc extraction device 26.

A ^99m Tc extraction device 26 is connected to each ⁹⁹ Mo solution tank 25. Therefore, a plurality of systems comprising the ⁹⁹ Mo solution tank 25 and the ^99m Tc extraction device 26 are formed. How many tandem lines are formed is important for on-demand response of diagnostic agents. Even in the case of two systems, it is possible to respond to on-demand requests in many cases.

^A plurality of ^99m Tc extraction devices are connected to the ⁹⁹ Mo solution storage means to form a ^99m Tc extraction system with a tandem configuration, and the entire device is extracted corresponding to the diagnostic agent on demand by independent ^99m Tc extraction for each tandem. A method or apparatus for producing medical technetium 99m is provided.

In this way, a plurality of ^99m Tc extraction devices 26 are individually connected to a plurality of ⁹⁹ Mo solution tanks 25, and technetium 99m is extracted with a time difference set for each individual ^99m Tc extraction device 26, and a plurality of them are connected. In addition, the entire ^99m Tc extraction device is extracted in response to a demand for diagnostic agents.

Tandem ^strains, 99 Mo solution storage means to ^99m Tc extractor equipped with the ^99m Tc extraction system of the plurality connected tandem configuration, the medical technetium 99m by independent ^99m Tc extraction instruction for each acquired tandem system extracts Is done.

In this way, the plurality of ^99m Tc extraction devices 26 can individually extract ^99m Tc serving as a diagnostic agent at different times. The width of the time difference corresponds to the time interval set by on-demand. Of course, a plurality of ^99m Tc extraction device ^26, a ^99m Tc, without shifting the time, it is also possible at the same time, but to extract separately.

In FIG. 2, ^99m Tc individually extracted from either one of the systems is sent to a ^99m Tc formulation device and shipped. The shipped ^99m Tc is quickly delivered to the ^99m Tc in consideration of the half-life according to means and methods predetermined by the pharmaceutical manufacturer or nuclear medicine center as the orderer.

According to this ^embodiment, by being extracted individually 99 Mo solution ^99m Tc from ⁹⁹ Mo individual ^99m Tc extractor multiple connected ^99m Tc extraction device to tank at different times, in which a plurality of connected ^{The 99m} Tc extraction system as a whole is configured as a system and system capable of performing tandem processing in parallel and capable of generating ⁹⁹ Mo more efficiently than reactor irradiation. Merits are sufficiently reflected in the production of ^99m Tc, which is a raw material for diagnostic agents, and a rapid and efficient ^99m Tc production method and system are proposed that are inexpensive and suitable for customer on-demand requirements.

That is, according to this embodiment, the manufacturing apparatus of the medical technetium-99m, raw Mo target, are the pellets formed contains ^{98 Mo,} to comprise pellets formed the ^{98 Mo,} neutron energy ⁹⁸ Neutrons from an accelerator neutron source controlled to be within the neutron resonance absorption band of Mo are irradiated under conditions that increase the neutron activation cross section by the irradiation, and ^99m Tc parent nuclide ⁹⁹ Mo is generated, ^{Stored in 99} Mo solution means,
The ^{99 Mo} solution plurality of ^{99m Tc} extraction device is connected to the storage means tandem system is the configuration, technetium 99m is extracted with a set time difference for each individual ^{99m Tc} extraction apparatus of a tandem system, a plurality of ^99m The entire apparatus is configured to be extracted corresponding to the diagnostic agent on demand by Tc extraction.

FIG. 10 is a view showing a modification of the manufacturing apparatus 100 for medical technetium 99m. The generated ^99m Tc parent nuclide ⁹⁹ Mo is stored in a paired Mo ( ⁹⁹ Mo) solution tank 25, and technetium 99m is extracted with a time difference set for each individual ^99m Tc extraction device, and a plurality of them are connected. The ^99m Tc extraction apparatus as a whole is the same as the manufacturing apparatus for medical technetium 99m described above in the inventive idea that extraction is performed corresponding to the diagnostic agent on demand. In the medical technetium 99m manufacturing apparatus 100 shown in FIG. 10, a Mo irradiation accelerator 180 is integrated, and a plurality of ^99m Tc extraction devices 26 and a Mo ( ⁹⁹ Mo) solution tank 25 are arranged in a straight line. There is a feature of being. With this configuration, the moving distance of the ⁹⁹ Mo solution for manufacturing medical technetium 99m is shortened.

In this example, Mo irradiation accelerator 180, Mo dissolved purifier ^{187, Mo (99} Mo) solution tank 25 and ^99m Tc extractor 26 is made integrally by the connection in series, medical technetium 99m as a whole The manufacturing system 200 is configured. The configuration of the medical technetium 99m manufacturing apparatus 100 is substantially the same as the above-described medical technetium 99m manufacturing apparatus. The same number is attached | subjected to the same structure or the functionally same part. These descriptions will be based on the description of FIG. 2 and other drawings. The manufacturing apparatus 100 for medical technetium 99m shown in FIG. 10 is placed horizontally because the Mo irradiation accelerator 180 is placed horizontally. Further, a water shielding wall 98 is provided around the shielding wall 15 of the hot cell disposed in the Mo irradiation accelerator 180. A machine room 99 is installed outside the external shielding wall 11, and an accelerator power supply, a cooling water circulation device, a ventilation, an exhaust device, and an emergency power supply are disposed in the machine room 99. The door 32 is made of Pb glass, and a simple manipulator is installed outside the door 32. Water shielding wall. Boric acid-containing concrete can be substituted.

The Mo dissolution purification device 187 may be directly connected to the ^99m Tc extraction device 26 by piping.

The Mo dissolution and purification device 187 is arranged side by side in the internal hot cell in which the ⁹⁹ Mo solution tank 25 is arranged, and the Mo ( ⁹⁹ Mo) solution is quickly transferred from the Mo dissolution and purification device 187 to the ⁹⁹ Mo solution tank 25. .

The Mo ( ⁹⁹ Mo) pellets are transferred from the Mo irradiation accelerator 180 to the Mo dissolution and purification device 187 by the pellet attachment / detachment / transfer device 41, and a moderator 42 is arranged around the thermal neutron irradiation portion.

Waste liquid and waste from the Mo dissolution and purification apparatus 187 and the ^99m Tc extraction apparatus 26 are made through the waste liquid and waste recovery system 61. In the case of this example, since the low-cost natural isotope ratio raw material Mo target is used, there is an advantage that the discarded natural isotope ratio raw material Mo target can be disposable. That is, accumulation of radioactive impurities due to multiple irradiations can be avoided.

  11 and 12 are diagrams showing a second embodiment of the present invention. The contents of the invention are basically the same as the invention shown in the first embodiment, and the description of the first embodiment is incorporated as it is. A description will be given focusing on a configuration that is not included in the first description and advantages over the first configuration.

Even in the second embodiment, as in the first embodiment, a natural isotope ratio raw material Mo target containing ⁹⁸ Mo as a target nucleus is irradiated with neutrons from an accelerator neutron source, and ^99m Tc parent nuclide ⁹⁹ Mo A method for producing technetium 99m for medical use, comprising:
1. The natural isotope ratio raw material Mo target is a pellet formed containing ⁹⁸ Mo,
2. A pellet formed containing ⁹⁸ Mo is irradiated with neutrons from an accelerator neutron source whose neutron energy is controlled to be within the neutron resonance absorption band of ⁹⁸ Mo, thereby producing ^99m Tc parent nuclide ⁹⁹ Mo. ,
3. Dissolve the irradiated pellets, purify the produced parent nuclide ⁹⁹ Mo,
4). It comprises a step consisting of extracting ^99m Tc from the purified parent nuclide ⁹⁹ Mo.

11 and 12, the present embodiment is a neutron irradiated apparatus that is irradiated with neutrons from a neutron irradiation apparatus, and is arranged in close proximity to the first pellet that is irradiated with neutrons from an accelerator neutron source. A plurality of ⁹⁹ Mo solution tanks arranged, a second pellet is arranged in close proximity to the ⁹⁹ Mo solution tank, a graphite is arranged in close proximity to the second pellet, and the second pellet There is an alternative to the first pellets, multiple ⁹⁹ Mo solution tank is relieved ⁹⁹ Mo attenuated by being neutron irradiation, ⁹⁹ Mo solution, respectively are extracted from a plurality of ⁹⁹ Mo solution ^tank, 99 Mo solution tank and the 1. A neutron irradiated apparatus in which the first and second pellets act as a neutron shield. In this configuration, the ⁹⁹ Mo solution tank is disposed so as to surround the first pellet from three sides, and the ⁹⁹ Mo solution tank functions as an apparatus for performing milking. This will be described below.

  FIG. 11 is a modification of the configuration of the neutron irradiated apparatus that is irradiated with neutrons from the neutron irradiation apparatus in the configuration shown in FIG. The neutron irradiated device 300 is disposed in close proximity to the horizontal direction, which is the irradiation direction of the neutron irradiation device 180 disposed horizontally. The irradiation state with respect to the pellet of the neutron irradiation apparatus 180 is the same as the state shown to FIG. 5 (A), (B), (E). In this example, the neutron irradiated apparatus 300 is arranged in close proximity to the pellet, that is, the first pellet.

  FIG. 12 is a diagram showing a detailed configuration of the neutron irradiation apparatus 300.

In FIG. 12, the neutron irradiated apparatus 300 is composed of a ⁹⁹ Mo solution tank, that is, a Mo tank, and pellets that are formed including ⁹⁸ Mo, that is, Mo pellets and graphite. As shown in FIGS. 5 (A), (B), and (E), the first pellet 192 (see FIG. 3) is placed in close proximity to the Be 191 in the horizontal direction, which is the irradiation direction of the neutron irradiation device 180 arranged horizontally. ) Is arranged. Mo tanks 301, 302, and 303 are arranged in close proximity to the first pellet. Each Mo tank 301, 302, 303 stores a ⁹⁸ Mo solution formed by dissolving irradiated pellets, and the Mo tanks 301, 302, 303 have a first structure as shown in FIG. It arrange | positions so that the pellet 192 may be surrounded from three directions. Although three Mo tanks are shown in FIG. 12, two or three Mo tanks may be provided, and a plurality of them are arranged. Each Mo tanks ^are installed extraction pipe for the 99 Mo solution extracted ^and allow 99 Mo solution extraction.

  In opposition to such Mo tanks 301, 302, and 303, Mo pellets 304, 305, and 306 are arranged so as to surround the Mo tanks 301, 302, and 303 from three sides. Mo pellets 304, 305, and 306 are Mo pellets immediately after being manufactured before irradiation, and constitute a second pellet. These second pellets 304, 305, 306 are aggregates of pellets shown in FIG. The second pellets 304, 305, and 306 are replaced with the first pellets 301, 302, and 303 to become the first pellets.

  The graphites 307, 308, and 309 are arranged so as to oppose and approach the second pellets 304, 305, and 306 and surround these pellets from three directions. As is well known, graphite is used as a neutron reflector.

  The arrangement of each member shown in FIG. 12 facilitates assembly of the neutron irradiated apparatus 300.

  The neutron irradiated apparatus 300 includes heavy concrete 310, 311 and 312 so as to surround these members from four directions. In this case, part of the heavy concrete 311, 312 and the Mo tanks 302, 303 form a neutron irradiation hole 193.

A plurality of Mo tanks 301, 302, 303 are arranged in close proximity to the first pellet irradiated with neutrons from the accelerator neutron source, and are arranged in close proximity to the Mo tanks 301, 302, 303. Two Mo pellets 304, 305, 306 are arranged, graphite 307, 308, 309 is arranged in close proximity to the second pellet, and the second pellet is replaced with the first pellet, Doing neutron irradiation in the first pellet 192, a plurality of Mo tanks 301, 302, and 303 are neutron irradiation, ⁹⁹ Mo attenuation in the Mo tank is relaxed, ⁹⁹ Mo, which is relaxed from a plurality of ⁹⁹ Mo solution tank The solution is extracted and the second pellet is also pre-irradiated with neutrons. When such irradiation is performed, the Mo tank and the second pellet act as a neutron shield.

  In the examples shown in FIGS. 11 and 12, heavy concrete 310, 311 and 312 are used as the surrounding material. However, the arrangement of heavy concrete is not provided or reduced by replacing with the shielding wall 15. It may be. Although the shielding wall 21 is not shown in FIG. 11, it is preferable to provide the shielding wall 21 in the same manner as in FIG. Also in this case, a door 33 is provided.

The produced parent nuclide ⁹⁹ Mo is extracted to the ^99m Tc extraction device 26 for each tandem system as a ⁹⁹ Mo solution. In this case, the Mo tanks 301, 302, and 303 are arranged close to the neutron irradiation device 180 and irradiated with neutrons, as shown in FIG. 10, and ⁹⁹ Mo attenuation in the Mo tank is reduced. In addition, the second pellet not only functions as a neutron shield, but also enables effective utilization of neutrons. It is excellent in terms of function and arrangement with respect to ⁹⁹ Mo attenuation.

According to the second embodiment, as in the first embodiment, a plurality of ^99m Tc extraction devices are connected to the ⁹⁹ Mo solution tank, and the technetium 99m has a time difference set for each individual ^99m Tc extraction device. By extracting for each tandem system, it is possible to extract a plurality of connected ^99m Tc extraction apparatuses corresponding to a medical diagnostic agent on demand. Thus, 50-fold efficiently than in the case of reactor irradiation can produce a parent nuclide ^{99 Mo} of ^{99m Tc,} this is reflected in the on-demand production of ^{99m Tc} as a raw material for diagnostics the benefits of, and less expensive Therefore, a method and / or system for producing technetium 99m for medical use is proposed that is suitable for on-demand demand for diagnostic reagents that are promptly provided by customers and that enables efficient production and formulation. Further, as described above, the ⁹⁹ Mo attenuation mitigating effect not obtained in the first embodiment can be obtained.
FIG. 13 is a diagram in which the first and second embodiments are compared with the comparative example. The present embodiment has significant advantages over other comparative examples in terms of comprehensive determination, practicality, and spread.

1 ... Production of MoO ₃ pellets, 2 ... Accelerator irradiation ⁹⁹ Mo production, 3 ... Accelerator irradiation ⁹⁹ Mo production, 4 ... ^99m Tc extraction recovery, 5 ... ^99m Tc production equipment, 6 ... ^99m Tc preparation equipment, 25 ... ⁹⁹ Mo Solution tank, 26 ... ^99m Tc extraction device, 100 ... Manufacturing apparatus for medical technetium 99m, 200 ... Manufacturing system for medical technetium 99m.

Claims (12)

Raw Mo target, are the pellets formed contains ^{98 Mo,} the pellets formed contains ^{98 Mo,} from the accelerator neutron source neutron energy is controlled to be within the neutron resonance absorption band of ^{98 Mo} Of ^99m Tc to generate ⁹⁹ Mo Tc parent ⁹⁹ Mo, and store it in ⁹⁹ Mo solution storage means.
The ^{99 Mo} solution plurality of ^{99m Tc} extraction device is connected to the storage means is configured tandem system, the technetium 99m is extracted with a set time difference for each individual ^{99m Tc} extraction apparatus of a tandem system, a plurality of ^99m A method for producing technetium 99m for medical use, characterized in that the entire device is extracted by Tc extraction in response to on-demand diagnostics. ^{In a} method for producing technetium 99m for medical use, comprising irradiating a natural isotope ratio raw material Mo target containing ⁹⁸ Mo as a target nucleus with neutrons from an accelerator neutron source to generate ^99m Tc parent nuclide ⁹⁹ Mo,
1. The natural isotope ratio raw material Mo target is a pellet formed containing ⁹⁸ Mo,
2. A pellet formed containing ⁹⁸ Mo is irradiated with neutrons from an accelerator neutron source whose neutron energy is controlled to be within the neutron resonance absorption band of ⁹⁸ Mo, thereby producing ^99m Tc parent nuclide ⁹⁹ Mo. ,
3. Dissolve the irradiated pellets, purify the produced parent nuclide ⁹⁹ Mo,
4). ^{Comprising the} step of extracting ^99m Tc from the purified parent nuclide ⁹⁹ Mo;
Natural isotopic ratio material Mo target, rather than concentrating Mo isotope, is a pellet formed contains ^{98 Mo} of natural isotopic ratio, the pellets formed contains ^{98 Mo} of natural isotopic ratio, neutron A neutron from an accelerator neutron source whose energy is controlled to be within the neutron resonance absorption band of ⁹⁸ Mo is irradiated under the condition that the neutron activation cross section by the irradiation increases, and ^99m Tc parent nuclide ⁹⁹ Mo is irradiated. Produced and stored in ⁹⁹ Mo solution storage means,
The ^{99 Mo} solution plurality of ^{99m Tc} extraction device is connected to the storage means is configured tandem system, the technetium 99m is extracted with a set time difference for each individual ^{99m Tc} extraction apparatus of a tandem system, a plurality of ^99m A method for producing technetium 99m for medical use, characterized in that the entire device is extracted by Tc extraction in response to on-demand diagnostics. The method of manufacturing a medical technetium 99m according to claim 1 or 2, tandem system is provided with ^{99m Tc} extracting apparatus of ^{99m Tc} extraction system of the plurality connected tandem configuration ^{99 Mo} solution storage means is acquired A method for producing medical technetium 99m, comprising extracting medical technetium 99m based on independent ^99m Tc extraction instructions for each tandem system. The method of manufacturing a medical technetium 99m according to claim 1 or ^2, 99 Mo solution means comprises a plurality of ⁹⁹ Mo solution tank, each ^99m Tc extraction device is connected to a plurality of ⁹⁹ Mo solution tank, technetium 99m ^Is extracted with a time difference set for each individual ^99m Tc extraction device, and the plurality of ^99m Tc extractions are performed in response to on-demand diagnostics as a whole device, and a method for producing technetium 99m for medical use. The method of manufacturing technetium 99m for medical use according to claim 1 or 2, wherein the ⁹⁹ Mo solution means is a plurality of ⁹⁹ arranged in close proximity to the first pellet irradiated with neutrons from the accelerator neutron source. ^99m Tc extraction device comprising a Mo solution tank, wherein the second pellet is arranged in close proximity to the ⁹⁹ Mo solution tank, the second pellet is replaced with the first pellet, and each of the ⁹⁹ Mo solution tanks Technetium 99m is extracted with a time difference set for each individual ^99m Tc extraction device, and the plurality of ^99m Tc extractions are performed in accordance with the diagnostic agent on demand as a whole device. Manufacturing method of technetium 99m. Raw Mo target, is a comprise pellets formed the ^{98 Mo,} to comprise pellets formed the ^{98 Mo,} neutrons from the controlled accelerator neutron source as the neutron energy is in the neutron resonance absorption band Irradiation is performed under the conditions that increase the neutron activation cross section by the irradiation, ^99m Tc parent nuclides ⁹⁹ Mo are generated, stored in ⁹⁹ Mo solution means,
The ^{99 Mo} solution plurality of ^{99m Tc} extraction device is connected to the storage means is configured tandem system, technetium 99m is extracted with a set time difference for each individual ^{99m Tc} extraction apparatus of a tandem system, a plurality of ^99m An apparatus for producing technetium 99m for medical use, characterized in that the entire apparatus is extracted by Tc extraction in correspondence with diagnostic on-demand. ^In a manufacturing apparatus for medical technetium 99m including irradiating a natural isotope ratio raw material Mo target containing ⁹⁸ Mo as a target nucleus with neutrons from an accelerator neutron source to generate ^99m Tc parent nuclide ⁹⁹ Mo,
1. The natural isotope ratio raw material Mo target is a pellet formed containing ⁹⁸ Mo,
2. A pellet formed containing ⁹⁸ Mo is irradiated with neutrons from an accelerator neutron source whose neutron energy is controlled to be within the neutron resonance absorption band of ⁹⁸ Mo, thereby producing ^99m Tc parent nuclide ⁹⁹ Mo. ,
3. Dissolve the irradiated pellets, purify the produced parent nuclide ⁹⁹ Mo,
4). ^{Comprising the} step of extracting ^99m Tc from the purified parent nuclide ⁹⁹ Mo;
Natural isotopic ratio material Mo target, rather than concentrating Mo isotope, is a pellet formed contains ^{98 Mo} of natural isotopic ratio, the pellets formed contains ^{98 Mo} of natural isotopic ratio, neutron Neutrons from an accelerator neutron source whose energy is controlled to be in the neutron resonance absorption band are irradiated under the condition that the neutron activation cross section by the irradiation increases, and ^99m Tc parent nuclide ⁹⁹ Mo is generated, ^{Stored in 99} Mo solution means,
The ^{99 Mo} solution plurality of ^{99m Tc} extraction device is connected to the storage means is configured tandem system, technetium 99m is extracted with a set time difference for each individual ^{99m Tc} extraction apparatus of a tandem system, a plurality of ^99m An apparatus for producing technetium 99m for medical use, characterized in that the entire apparatus is extracted by Tc extraction in correspondence with diagnostic on-demand. Apparatus for manufacturing a medical technetium 99m according to claim 6 or 7, tandem system is provided with ^{99m Tc} extracting apparatus of ^{99m Tc} extraction system of the plurality connected tandem configuration ^{99 Mo} solution storage means is acquired An apparatus for producing medical technetium 99m, wherein medical technetium 99m is extracted based on independent ^99m Tc extraction instructions for each tandem system. Apparatus for manufacturing a medical technetium 99m according to claim 6 or ^7, 99 Mo solution means comprises a plurality of ⁹⁹ Mo solution tank, each ^99m Tc extraction device is connected to a plurality of ⁹⁹ Mo solution tank, technetium 99m Is extracted with a time difference set for each individual ^99m Tc extraction device, and is extracted in response to on-demand diagnostics as a whole device by a plurality of ^99m Tc extractions, and a manufacturing apparatus for medical technetium 99m . Apparatus for manufacturing a medical technetium 99m according to claim 6 or 7, ^{99 Mo} solution means, a plurality of neutrons from an accelerator neutron source is arranged close against the first pellet to be irradiated ^{99 99m} Tc extraction device comprising a Mo solution tank, wherein the second pellet is arranged in close proximity to the ⁹⁹ Mo solution tank, the second pellet is replaced with the first pellet, and each of the ⁹⁹ Mo solution tanks Technetium 99m is extracted with a time difference set for each individual ^99m Tc extraction device, and the entire device is extracted corresponding to the diagnostic agent on-demand by a plurality of ^99m Tc extractions. Equipment for manufacturing technetium 99m. A neutron irradiated apparatus that is used in the medical technetium 99m manufacturing apparatus according to claim 6 or 7 and that is irradiated with neutrons from a neutron irradiation apparatus, the first being irradiated with neutrons from an accelerator neutron source A plurality of ⁹⁹ Mo solution tanks arranged in close proximity to the pellets are arranged, and a second pellet is arranged in close proximity to the ⁹⁹ Mo solution tanks, in opposition to and close to the second pellets. Graphite is arranged, the second pellet is replaced with the first pellet, and the ⁹⁹ Mo solution tank is irradiated with neutrons to reduce ⁹⁹ Mo attenuation, and each of the ⁹⁹ Mo solution tanks has a ⁹⁹ Mo solution. The extracted neutron irradiated apparatus, wherein the ⁹⁹ Mo solution tank and the first and second pellets act as a neutron shield. 12. The neutron irradiated apparatus according to claim 11, wherein a ⁹⁹ Mo solution tank is disposed surrounding the first pellet from three directions.

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