System and method enabling the behavior of radioactive materials in a structure to be determined - Patents.com

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 allows for determining the location and distribution of radioactive material within a structure, the rate of movement of the radioactive material within the structure, and the time at which the radioactive material exits the structure. [Background technology]

[0002] For the production of some radioactive solutions, it is preferred to carry out the production by a method in which no carrier atoms are added, i.e., by the no-carrier-added (NCA) method. The production of Lu-177 radiolabeled solutions is also produced by the NCA method. The production of Lu-177 solutions was first achieved in 1994 by Balasubramanium by neutron irradiation of ytterbium. In this method, Yb176 is converted to Yb177 by a neutron capture reaction, and Lu-177 forms as a result of beta decay (half-life = 1.9 hours) of the formed Yb177. Lu-177 with high specific activity forms as a result of this process, and the product formed is called "no-carrier-added" Lu177. The production method is NCA because only a single carrier (Lu-177) forms in the finished product resulting from the nuclear np reaction. However, because the finished product contains macro amounts of ytterbium-176 and trace amounts of lutetium-177, which have chemically similar properties, and because ytterbium-176 is limited in the drug class of the finished product and, more importantly, is required not to be present in the finished product from the perspective of drug activity, a 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 literature, a separation and purification system was designed. The main challenge of the method is the need to separate 176Yb and 177Lu, since 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 loaded into a column with an acid of a certain molar concentration. An acid of another molar concentration is passed through the column to drive the loaded substances through the column. The substances to be separated move from top to bottom along the upright column at a certain speed. The column creates a phase difference for the radioactive substances passing through the column according to the nature of the resin used in the column, thereby resulting in the movement of the radioactive substances within the column. Knowing the rate of movement of the substances within the column and the time at which they leave the column affects the efficiency of solid phase extraction. In current state-of-the-art devices used for solid phase extraction chromatography, fixed radioactivity detectors are used. These detectors are positioned at the inlet or outlet of the column or at the cartridge, depending on the physical characteristics of the device. The radioactive substances moving inside the column or cartridge wait to reach the column outlet and are allowed to proceed to the next process step depending on the activity value read by the detector. The problem here is that the maximum radioactivity of the material and the extent to which it is distributed in the column cannot be known until the material is in front of the detector. Knowing these values ​​before the material reaches the column outlet allows the next process step to be taken at the optimal point and the process to be controlled by automation. Summary of the Invention [Problem to be solved by the invention]

[0004] The system and method of the present invention eliminates the problem posed by the use of fixed detectors of not knowing the location and extent of distribution of radioactivity in a column or cartridge until the material is in front of the detector, and makes it possible to monitor the location and distribution of material moving within the column along the column. [Means for solving the problem]

[0005] It is an object of the present invention to develop a system and method that makes it possible to determine the position and / or distribution of a substance migrating within a column and / or its migration velocity along the column and / or its column exit time.

[0006] Another object of the present invention is to develop a system and method that makes it possible to determine how much of the material reaching the column outlet begins to leave the column at what radioactivity.

[0007] Another object of the present invention is to develop a system and method in which the possibility of determining how much of the material reaching the column outlet starts to leave the column at what radioactivity provides optimization and automation for proceeding to the next process step. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an isometric view of a system according to the present invention. [Diagram 2] FIG. 2 is another isometric view of the system according to the present invention. [Diagram 3] 1 is a cross-sectional view of a system according to the present invention; [Figure 4] FIG. 2 is a cross-sectional view of a radiation detector and a detector collimator. [Diagram 5] FIG. 2 is an exploded view of a radiation detector and a detector collimator. [Figure 6] FIG. 2 is a diagram of a radiation detector and a detector collimator fixed to a detector carrier. [Figure 7] FIG. 2 is a cross-sectional view of a radiation detector and a detector collimator secured to a detector carrier. [Figure 8] FIG. 2 is a cross-sectional view of a radiation detector and a detector collimator fixed to a detector carrier by two connecting members. [Figure 9] 2 is a graph showing the distribution of materials undergoing separation in a column. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention relates to a system and a method that allows the behavior of radioactive material in a structure to be determined, more particularly to a system and a method that makes it possible to determine along a column (2) the position and / or the distribution and / or the speed of movement of the material in the column (2) and / or the time at which the material leaves the column (2) and at what radioactivity what proportion of the material that reaches the column outlet (23) starts to leave the column (2), thus providing an optimization and automation for proceeding to the next process steps.

[0010] In its most basic form, the system according to the invention comprises at least one column (2) through which radioactive material moves, at least one radioactivity detector (5) enabling detection of the radioactive material in the column (2), and at least one actuator (31) enabling the radioactivity detector (5) to move 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 step 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), on which the radioactivity detector (5) moves. 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 of the ends of the rotating shaft (33) is supported in the bearing member (351) so that the rotating shaft (33) is free to rotate. The bearing member (351) is preferably a bearing. The other end of the rotating shaft (33) is fixed to an actuator (31) that is positioned on a second fixing member (36). A preferred embodiment of the present invention includes at least one coupling (32) that provides a connection between the actuator (31) and a rotating shaft (33) and enables 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) in which a radioactive detector (5) is positioned and moves with the detector carrier (4). In this embodiment, the detector carrier (4) has at least one rotating shaft bearing (41) through which a rotating shaft (33) is to pass and is to be supported. In a preferred embodiment of the present invention, the rotating shaft (33) has a toothed structure. The rotating shaft bearing (41) located on the detector carrier (4) also has a toothed structure. The rotating shaft (33) and the rotating shaft bearing (41) have a matching toothed structure to allow the rotating shaft bearing (41) and therefore the detector carrier (4) to move on the rotating shaft (33) according to the rotational movement and direction of the rotating shaft (33).

[0014] A preferred embodiment of the invention comprises at least one fixed shaft (34), which allows the detector carrier (4) to move in different directions only on a single axis without any rotational movement. Said fixed shaft (34) is positioned between a first fixing member (35) and a second fixing member (36). In this embodiment of the invention, the detector carrier (4) comprises 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). In this way, the rotating shaft (33) having a toothed structure, which rotates in response to the rotational movement of the actuator (31), rotates inside the rotating shaft bearing (41) having a toothed structure, and since the detector carrier (4) is fixed to the fixed shaft (34) by the fixed shaft bearing (42), the detector carrier (4) and therefore the rotating shaft bearing (41) cannot rotate, and 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 on the fixed shaft (34) in various directions, approaching the first fixing member (35) or the second fixing member (36), depending on the rotation direction of the rotating shaft (33).

[0015] A preferred embodiment of the present invention has at least one detector collimator (51) in which the 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 pre-collimator (52) and at least one collimator cover (53). The radioactivity detector (5) is positioned into the pre-collimator (52) and is fixed when the collimator cover (53) is closed. The pre-collimator (52) has at least one collimator opening (54). The pre-collimator (52) further has at least one cable space (56) for allowing the radioactivity detector cable (55) to pass through.

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

[0017] The detector collimator (51) is fixed in a housing in the detector carrier (4) and is therefore allowed to move with the detector carrier (4). The distance of the collimator opening (54) from the column (2) is an important parameter for the radioactivity detector (5) to be able to make a reliable radioactivity reading. If the radioactivity of the material passing through the column (2) is high, the radioactivity detector (5) may become saturated. To prevent this from happening, the diameter of the collimator opening (54) needs to be reduced or the radioactivity detector (5) needs to be moved away from the column (2). For this reason, it is desirable that the detector collimator (51) can be fixed at various positions in the housing in the detector carrier (4). For this purpose, at least one, and preferably more than one, connecting member (6) is used to fix the detector collimator (51) to the detector carrier (4). There are more than one bearing of the connecting members (6) in the detector carrier (4) and when the detector collimator (51) is brought to the desired position in the detector carrier (4), the fixing action is achieved by the connecting members (6) positioned into the bearings of the appropriate connecting members (6). In a preferred embodiment, the pre-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 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) mentioned within the scope of the present invention comprises 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 leaves the column body (21). At least one plug (24) is positioned at the end of the column inlet (22) and / or at the end of the column outlet (23) of the column body (21). Said plug (24) is fixed by at least one cover (25) so as to be able to withstand the pressure inside the column body (21). Said cover (25) is preferably a toothed cover (25).

[0020] A preferred embodiment of the invention comprises at least one platform (1) on which the column (2) and / or the rotating shaft (33), on which the radioactivity detector (5) moves, and / or the fixed shaft (34) are positioned. In said embodiment, the fixed shaft (34) and the rotating shaft (33) are positioned in a second fixing member (36) fixed to the platform (1). The column (2), the rotating shaft (33) and the fixed shaft (34) are positioned such that the distance of the radioactivity detector (5) from the column (2) always remains constant and said radioactivity detector (5) can scan the column (2) over its entire length.

[0021] The method according to the invention comprises the following process steps: loading the radioactive material into the column (2) via the column inlet (22) together with an acid of a specific molar concentration; collecting radioactive material at the top of the column body (21), more specifically at the column inlet (22); Leading the acid used for packing to waste via the column outlet (23); modifying the molarity of the acid introduced at the column inlet (22) and thus allowing the loaded radioactive material intended to be separated to migrate within the column (2); moving the radioactivity detector (5) along the column body (21) after the start of said movement and achieving a scanning process; Includes.

[0022] The acid passed through the column (2) creates a pressure inside the column (2) in the range of 3 to 11 bar.

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

[0024] The step of modifying the molar concentration of the acid introduced into the column inlet (22) and thus allowing the loaded radioactive material intended to be separated to move within the column (2), the movement being from the end of the column inlet (22) towards the end of the column outlet (23).

[0025] The speed of movement of the radioactivity detector (5) along the column body (21) is adjusted depending on the rotation speed of the actuator (31).

[0026] In a preferred embodiment of the invention, the 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, then stops and waits, the radioactivity value is read at the current position, the radioactivity detector (5) moves over a certain distance again and another reading process is performed.

[0027] As a result of the scan performed, information about the extent to which the radioactive material is distributed in the column (2) and its position within the column (2) can be obtained on an activity-distance graph. Zones A and B in the graph shown in Figure 9 show the distribution of the radioactive material separated in the column (9). Since the transition point from zone A to zone B is known in advance, it is possible to proceed automatically to the next process step when the transition zone reaches the exit of the column (2). [Explanation of symbols]

[0028] 1 unit 2 Columns 21 Column body 22 Column inlet 23 Column outlet 24 Plug 25 Cover 31 Actuator 32 Coupling 33 Rotating shaft 34 Fixed shaft 35 First fixing member 351 Bearing parts 36 Second fixing member 4 Detector Carrier 41 Rotating shaft bearing 42 Fixed shaft bearing 5. Radiation detector 51 Detector collimator 52 Front collimator 53 Collimator cover 54 Collimator Aperture 55 Detector cable 56 Cable Space 6 Connection parts

Claims

1. A system making it possible to determine the behavior of radioactive materials in a structure, comprising: at least one column (2) through which the radioactive material travels; at least one radioactivity detector (5) making it possible to detect said radioactive material in said column (2); at least one actuator (31) enabling said radioactivity detector (5) to move along said column (2); A system comprising:

2. The system includes at least one rotating shaft (33), the at least one rotating shaft (33) rotates in response to a rotational movement of the actuator (31), the radioactivity detector (5) moves on the at least one rotating shaft (33), 2. The system according to claim 1, characterized in that the system comprises at least one first fixing member (35) and at least one second fixing member (36) enabling the rotating shaft (33) to be fixed.

3. The system described in claim 2, characterized in that the system comprises at least one bearing member (351) enabling the rotating shaft (33) to be supported so that the rotating shaft (33) can freely perform rotational movement about its own central axis.

4. One end of the rotating shaft (33) is connected to the actuator (31), 3. The system according to claim 2, characterized in that the system comprises at least one coupling (32) which enables a connection between the actuator (31) and the rotating shaft (33) to be established and enables the rotational movement of the actuator (31) to be transmitted to the rotating shaft (33).

5. A system as described in any one of claims 1 to 4, characterized in that 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).

6. A system as described in claim 5, characterized in that the detector carrier (4) has at least one rotating shaft bearing (41) through which the rotating shaft (33) passes and is supported.

7. The system described in claim 6, 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 the rotating shaft (33).

8. The system described in claim 5, characterized in that the system comprises at least one fixed shaft (34), which enables the detector carrier (4) to move in different directions only on a single axis without performing rotational movement.

9. A system as described in any one of claims 1 to 8, characterized in that the system comprises at least one detector collimator (51), and the radioactivity detector (5) is positioned within the at least one detector collimator (51).

10. 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 of claim 9, wherein the pre-collimator (52) has at least one collimator opening (54).

11. A system described in any one of claims 1 to 10, characterized in that 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).

12. The column body (21) includes at least one plug (24) at an end of the column inlet (22) and / or at an end of the column outlet (23); 12. The system according to claim 11, characterized in that the plug (24) is fixed by at least one cover (25) so as to be able to withstand the pressure inside the column body (21).

13. The system described in claim 2 or 8, characterized in that the system comprises at least one table (1) on which the column (2) and / or the rotating shaft (33) on which the radioactivity detector (5) moves and / or the fixed shaft (34) are positioned.

14. The system described in claim 13, characterized in that the column (2) and / or the rotating shaft (33), on which the radioactivity detector (5) moves, and / or the fixed shaft (34), are positioned on the table (1) so that the distance of the radioactivity detector (5) from the column (2) remains constant at all times and so that the radioactivity detector (5) can scan the column (2) over its entire length.

15. A method making it possible to determine the behavior of radioactive materials in a structure, comprising the following process steps: loading said radioactive material into a column (2) via a column inlet (22) together with an acid of a specific molar concentration; collecting said radioactive material at the top of the column body (21), more specifically at the end of the column inlet (22); Leading the acid used for packing to waste via the column outlet (23); modifying the molarity of the acid introduced at the column inlet (22) and thus allowing the loaded radioactive material intended to be separated to move within the column (2); moving a radioactivity detector (5) along the column body (21) after the start of said movement; performing a scanning process; A method comprising:

Images