A system and method that enables the determination of the behavior of radioactive materials within a structure.

Abstract

The present invention relates to a system and a method that allows the behavior of radioactive material within a structure to be determined, more particularly to a system and a method that allows the determination of the position and / or distribution and / or movement speed of material moving within the column (2), along the column (2), and / or the time at which the material leaves the column (2), and also the percentage of material that reaches the column outlet (23) and at what radioactivity starts to leave the column (2), thus providing optimization and automation for proceeding to the next process step.

Description

Technical Field

[0001] The present invention relates to a system and method that enable determination of the position and distribution of radioactive substances within a structure, the movement speed of radioactive substances within the structure, and the time when radioactive substances exit the structure.

Background Art

[0002] Regarding the production of some radioactive solutions, it is preferable to perform the production by a method in which carrier atoms are not added, that is, by a carrier-free (NCA) method. The production of Lu-177 radiolabeled solutions is also carried out by the NCA method. The production of Lu-177 solutions was first achieved by Balasubramanium in 1994 by neutron irradiation of ytterbium. In this method, Yb176 is converted to Yb177 by a neutron capture reaction, and as a result of the beta decay (half-life = 1.9 hours) of the formed Yb177, Lu-177 is formed. Lu-177 having a high specific radioactivity is formed as a result of this process, and the formed product is called "carrier-free" Lu177. The production method is NCA because only a single carrier (Lu-177) is formed in the finished product resulting from the nuclear np reaction. However, the finished product contains a macro amount of ytterbium 176 having chemically similar properties and a trace amount of lutetium 177, and ytterbium 176 is restricted in the drug species of the finished product. More importantly, it is required not to be present in the finished product from the viewpoint of drug activity. Therefore, chemical separation must be performed (Horwitz, A process for the separation of 177Lu from neutiron irradiated 176Yb targets, Applied Radiation and isotopes, 63(2005)23-36). Based on the basic information in this document, a separation and purification system was designed. The main problem of the method is the need to separate 176Yb and 177Lu because they are chemically similar elements.

[0003] Extraction chromatography separates two or more radioactive substances with very similar chemical properties that are dissolved in a suitable solvent. The radioactive substances are packed into a column with an acid of a specific molar concentration. Another acid of a different molar concentration is passed through the column to propel the packed substances through it. The substances to be separated move at a specific speed from top to bottom along an upright column. The column, according to the properties of the resin used within it, creates a phase difference for the radioactive substances passing through it, thereby facilitating their movement. Knowing the rate of movement of the substances within the column and the time it takes for them to exit the column affects the efficiency of solid-phase extraction. In current state-of-the-art devices used in solid-phase extraction chromatography, fixed radioactivity detectors are employed. These detectors are positioned at the inlet or outlet of the column or in a cartridge, depending on the physical characteristics of the device. The radioactive substances moving within the column or cartridge wait to reach the column outlet, and are allowed to proceed to the next process step depending on the radioactivity (activity) value read by the detector. The challenge here is that we cannot know the maximum radioactivity of a substance or the range in which it is distributed within the column until the substance reaches the detector. Knowing these values ​​before the substance reaches the column exit allows us to proceed to the next process step at the optimal point and to manage the process through automation. [Overview of the project] [Problems that the invention aims to solve]

[0004] The system and method according to the present invention eliminate the problem caused by the use of a fixed detector, which is that the position and distribution range of radioactivity in a column or cartridge cannot be known until the substance comes in front of the detector, and makes it possible to monitor the position and distribution of a substance moving within the column along the column. [Means for solving the problem]

[0005] One objective of the present invention is to develop a system and method that makes it possible to determine the position and / or distribution of a substance moving within a column and / or its migration speed along the column and / or its exit time from the column.

[0006] Another object of the present invention is to develop a system and method that makes it possible to determine what percentage of the material reaching the column outlet will begin to exit the column with what level of radioactivity.

[0007] Another object of the present invention is to develop a system and method that provides optimization and automation for proceeding to the next process step by making it possible to determine how much of the material reaching the column outlet will begin to exit the column with what level of radioactivity. [Brief explanation of the drawing]

[0008] [Figure 1] This is an isometric projection view of the system according to the present invention. [Figure 2] This is another isometric projection view of the system according to the present invention. [Figure 3] This is a cross-sectional view of the system according to the present invention. [Figure 4] This is a cross-sectional view of a radioactivity detector and a detector collimator. [Figure 5] This is an exploded view of a radioactive detector and detector collimator. [Figure 6] This is a diagram of a radioactive detector and detector collimator fixed to a detector carrier. [Figure 7] This is a cross-sectional view of a radioactive detector and a detector collimator fixed to a detector carrier. [Figure 8] This is a cross-sectional view of a radioactivity detector and a detector collimator, which are fixed to a detector carrier by two connecting members. [Figure 9] This graph shows the distribution of substances undergoing separation within the column. [Modes for carrying out the invention]

[0009] The present invention relates to a system and method that enables the determination of the behavior of radioactive material within a structure. More specifically, the present invention relates to a system and method that makes it possible to determine the position and / or distribution and / or velocity of material moving along a column (2), and / or the time it takes for the material to leave the column (2), and how much of the material that reaches the column outlet (23) begins to leave the column (2) with what level of radioactivity, and thus can provide optimization and automation for proceeding to the next process step.

[0010] In its most basic form, the system according to the present invention comprises at least one column (2) through which radioactive material moves, at least one radioactivity detector (5) capable of detecting radioactive material within the column (2), and at least one actuator (31) capable of moving the radioactivity detector (5) along the column (2).

[0011] In a preferred embodiment of the present invention, the actuator (31) is a motor. More specifically, the actuator (31) is a stepper motor or a servo motor.

[0012] A preferred embodiment of the present invention includes at least one rotating shaft (33) that rotates in a manner dependent on an actuator (31), and a radioactivity detector (5) moves along the rotating shaft (33). The rotating shaft (33) is positioned between at least one first fixing member (35) and at least one second fixing member (36). A preferred embodiment of the present invention includes at least one bearing member (351) that allows the rotating shaft (33) to rotate freely about its own central axis. The bearing member (351) is preferably fixed to the first fixing member (35), and one end of the rotating shaft (33) is supported within the bearing member (351) so that the rotating shaft (33) can rotate freely. The bearing member (351) is preferably a bearing. The other end of the rotating shaft (33) is fixed to an actuator (31) which is positioned on the second fixing member (36). A preferred embodiment of the present invention includes at least one coupling (32) which provides a connection between the actuator (31) and the rotating shaft (33), allowing the rotational motion of the actuator (31) to be transmitted to the rotating shaft (33).

[0013] A preferred embodiment of the present invention includes at least one detector carrier (4) on which a radioactivity detector (5) is positioned, and the radioactivity detector (5) moves together with the detector carrier (4). In this embodiment, the detector carrier (4) has at least one rotating shaft bearing (41) on which a rotating shaft (33) passes and is supported. In a preferred embodiment of the present invention, the rotating shaft (33) has a toothed structure. The rotating shaft bearing (41) positioned on the detector carrier (4) also has a toothed structure. The rotating shaft (33) and the rotating shaft bearing (41) have matching toothed structures to enable the rotating shaft bearing (41) and thus the detector carrier (4) to move on the rotating shaft (33) in accordance with the rotational motion and direction of rotation of the rotating shaft (33).

[0014] A preferred embodiment of the present invention includes at least one fixed shaft (34) which allows the detector carrier (4) to move in different directions only on a single axis without rotational motion. The fixed shaft (34) is positioned between a first fixing member (35) and a second fixing member (36). In this embodiment of the present invention, the detector carrier (4) includes at least one fixed shaft bearing (42) through which the fixed shaft (34) passes and which allows the detector carrier (4) to move on the fixed shaft (34). Thus, the toothed rotating shaft (33), which rotates in accordance with the rotational motion of the actuator (31), rotates inside the toothed rotating shaft bearing (41), and since the detector carrier (4) is fixed to the fixed shaft (34) by the fixed shaft bearing (42), the detector carrier (4) and consequently the rotating shaft bearing (41) cannot rotate. Due to the toothed structure of the rotating shaft (33) and the toothed structure of the rotating shaft bearing (41), the detector carrier (4) moves along the fixed shaft (34) in various directions depending on the rotational direction of the rotating shaft (33), approaching either the first fixing member (35) or the second fixing member (36).

[0015] A preferred embodiment of the present invention has at least one detector collimator (51) in which a radioactivity detector (5) is positioned. The detector collimator (51) preferably has a two-piece structure. In this embodiment, the detector collimator (51) includes at least one front collimator (52) and at least one collimator cover (53). The radioactivity detector (5) is positioned in the front collimator (52) and secured when the collimator cover (53) is closed. The front collimator (52) has at least one collimator opening (54). The front collimator (52) further has at least one cable space (56) to allow a radioactivity detector cable (55) to pass through.

[0016] In a preferred embodiment of the present invention, the collimator cover (53) is fixed to the front collimator (52) without the use of any connecting member (6). As a result, the front collimator (52) and the collimator cover (53) can be easily separated when it is necessary to replace the radioactivity detector (5) and / or when it is necessary to use a front collimator (52) having a collimator opening (54) of a different size.

[0017] The detector collimator (51) is fixed within the housing in the detector carrier (4) and is therefore allowed to move with the detector carrier (4). The distance of the collimator aperture (54) from the column (2) is an important parameter that allows the radioactivity detector (5) to reliably read radioactivity. If the radioactivity of the substance passing through the column (2) is high, the radioactivity detector (5) may become saturated. To prevent this from happening, it is necessary to reduce the diameter of the collimator aperture (54) or to move the radioactivity detector (5) away from the column (2). For this reason, it is desirable that the detector collimator (51) can be fixed at various positions within the housing in the detector carrier (4). For this reason, at least one, preferably more than one, connecting members (6) are used to fix the detector collimator (51) to the detector carrier (4). If the detector carrier (4) has more than one bearing for the connecting member (6), and the detector collimator (51) is brought to a desired position on the detector carrier (4), then fixing is achieved by the connecting member (6) positioned within the appropriate bearing for the connecting member (6). In a preferred embodiment, the front collimator (52) is fixed to the detector carrier (4) by at least one connecting member (6), and the collimator cover (53) is fixed to the detector carrier (4) by at least one connecting member (6).

[0018] In a preferred embodiment of the present invention, the detector carrier (4) has at least one cable space (56) through which a radioactivity detector cable (55) can pass.

[0019] The column (2) described within the scope of the present invention includes at least one column body (21), at least one column inlet (22) through which radioactive substances enter the column body (21), and at least one column outlet (23) through which radioactive substances exit the column body (21). At least one plug (24) is positioned at the end of the column inlet (22) and / or the end of the column outlet (23) of the column body (21). The plug (24) is fixed by at least one cover (25) so as to withstand the pressure inside the column body (21). The cover (25) is preferably a toothed cover (25).

[0020] A preferred embodiment of the present invention includes a column (2) and / or a rotating shaft (33) on which a radiation detector (5) moves, and / or at least one base (1) on which a fixed shaft (34) is positioned. In the above embodiment, the fixed shaft (34) and the rotating shaft (33) are positioned within a second fixing member (36) fixed to the base (1). The column (2), the rotating shaft (33), and the fixed shaft (34) are positioned such that the distance from the radiation detector (5) to the column (2) always remains constant and the radiation detector (5) can scan the entire length of the column (2).

[0021] The method according to the present invention includes the following process steps, namely filling the column (2) with radioactive substances through the column inlet (22) together with an acid of a specific molar concentration; collecting radioactive substances at the upper part of the column body (21), more specifically at the column inlet (22); leading the acid used for filling to waste liquid through the column outlet (23); changing the molar concentration of the acid introduced into the column inlet (22), and thus enabling the filled radioactive substances intended to be separated to move within the column (2); The steps include moving the radioactivity detector (5) along the column body (21) after the above movement has started and completing the scanning process, Includes.

[0022] The acid passed through column (2) creates a pressure inside column (2) ranging from 3 to 11 bar.

[0023] The radioactivity detector (5) moves along the column body (21) from top to bottom, more specifically from the end of the column inlet (22) to the end of the column outlet (23).

[0024] In the step of changing the molar concentration of the acid introduced into the column inlet (22), thereby allowing the packed radioactive material intended to be separated to move within the column (2), the movement is from the end of the column inlet (22) to the end of the column outlet (23).

[0025] The speed at which the radioactivity detector (5) moves along the column body (21) is adjusted according to the rotational speed of the actuator (31).

[0026] In a preferred embodiment of the present invention, scanning is performed continuously, in other words, the radioactivity detector (5) moves continuously. In another preferred embodiment, the radioactivity detector (5) moves over a certain distance, stops and waits, and once the radioactivity value is read at the current position, the radioactivity detector (5) moves again over a certain distance for another reading process.

[0027] The scan results allow us to see information about the extent to which the radioactive material is dispersed within column (2) and its location within column (2) on a radioactivity-distance graph. Zones A and B in the graph shown in Figure 9 represent the distribution of the radioactive material separated within column (9). Since the transition point from zone A to zone B is known in advance, the process can proceed to the next step automatically when the transition zone reaches the exit of column (2). [Explanation of symbols]

[0028] 1 unit 2 columns 21 Column body 22 Column Entrance 23 Column Exit 24 plugs 25 Cover 31 Actuator 32 Coupling 33 Rotating shaft 34 Fixed shaft 35 First fixing member 351 Bearing member 36 Second fixing member 4 Detector carrier 41 Rotating shaft bearing 42 Fixed shaft bearing 5. Radioactivity detector 51 Detector collimator 52 Front collimator 53 Collimator Cover 54 Collimator aperture 55 Detector Cable 56 Cable Space 6. Connecting Members

Claims

1. A system that makes it possible to determine the behavior of radioactive materials within a structure, The radioactive material passes through at least one column (2), The column (2) includes at least one radioactivity detector (5) that enables the detection of the radioactive material within it, The radioactivity detector (5) is provided with at least one actuator (31) that allows it to move along the column (2), Equipped with, The system comprises at least one detector carrier (4), the radioactivity detector (5) is positioned on the at least one detector carrier (4), and the radioactivity detector (5) moves together with the at least one detector carrier (4). The system is characterized in that it comprises at least one detector collimator (51), and the radioactivity detector (5) is positioned within the at least one detector collimator (51).

2. The system comprises at least one rotating shaft (33), the at least one rotating shaft (33) rotates in accordance with the rotational motion of the actuator (31), and the radioactivity detector (5) moves along the at least one rotating shaft (33). The system according to claim 1, further comprising at least one first fixing member (35) and at least one second fixing member (36) that enable the rotating shaft (33) to be fixed.

3. The system according to claim 2, further comprising at least one bearing member (351) that enables the rotating shaft (33) to be supported so that it can freely rotate around its own central axis.

4. One end of the rotating shaft (33) is connected to the actuator (31), The system according to claim 2, further comprising at least one coupling (32), the at least one coupling (32) enabling connection between the actuator (31) and the rotating shaft (33) and enabling the rotational motion of the actuator (31) to be transmitted to the rotating shaft (33).

5. The system according to claim 1, characterized in that the detector carrier (4) has at least one rotating shaft bearing (41) through which a rotating shaft (33) passes and which supports it.

6. The system according to claim 5, characterized in that the rotating shaft (33) and the rotating shaft bearing (41) have a matching toothed structure that enables the rotating shaft bearing (41) and thus the detector carrier (4) to move on the rotating shaft (33) in accordance with the rotational motion and direction of rotation of the rotating shaft (33).

7. The system according to claim 1, further comprising at least one fixed shaft (34), wherein the at least one fixed shaft (34) allows the detector carrier (4) to move in different directions only on a single axis without rotational motion.

8. The detector collimator (51) has a two-piece structure, The detector collimator (51) includes at least one pre-collimator (52) and at least one collimator cover (53), The system according to claim 1, characterized in that the front collimator (52) has at least one collimator aperture (54).

9. The system according to any one of claims 1 to 8, wherein the column (2) includes at least one column body (21), at least one column inlet (22) through which the radioactive material enters the column body (21), and at least one column outlet (23) through which the radioactive material exits the column body (21).

10. The column body (21) includes at least one plug (24) at the end of the column inlet (22) and / or the end of the column outlet (23), The system according to claim 9, characterized in that the plug (24) is secured by at least one cover (25) so as to be able to withstand the internal pressure of the column body (21).

11. The system according to claim 2 or 7, characterized in that it comprises the column (2) and / or rotating shaft (33), the rotating shaft (33) on which the radioactivity detector (5) moves, and / or the stationary shaft (34) on which the rotating shaft (33) and / or stationary shaft (34) are positioned.

12. The system according to claim 11, wherein the column (2) and / or the rotating shaft (33), on which the radioactivity detector (5) moves, is positioned on the stand (1) such that the distance of the radioactivity detector (5) from the column (2) remains constant and the radioactivity detector (5) can scan the column (2) along its entire length.

13. A method that enables the determination of the behavior of radioactive material within a structure, comprising the following process steps, namely The steps include: filling the column (2) with the radioactive material together with an acid of a specific molar concentration via the column inlet (22); The steps include collecting the radioactive material at the top of the column body (21), more specifically at the end of the column inlet (22), The steps include: guiding the acid used for packing to waste liquid via the column outlet (23); The steps include changing the molar concentration of the acid introduced into the column inlet (22) and thus allowing the packed radioactive material intended to be separated to move within the column (2), The steps include moving the radioactivity detector (5) along the column body (21) after the start of the aforementioned movement, Steps to achieve the scanning process, Includes, The radioactivity detector (5) is positioned on at least one detector carrier (4), and the radioactivity detector (5) moves together with the at least one detector carrier (4), A method characterized in that the radioactivity detector (5) is positioned within at least one detector collimator (51).

14. The system according to claim 8, wherein the detector collimator (51) is fixed at multiple positions within the housing of the detector carrier (4), thereby changing the distance of the collimator opening (54) from the column (2).

Images