Target delivery system for a radionuclide generation system
By using multiple distance sensors and a pattern recognition algorithm to calculate intermediate signals in the target delivery system, the problem of inaccurate target counting in the prior art has been solved, and accurate counting of the number of targets entering or leaving the nuclear reactor core has been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FRAMATOME GMBH
- Filing Date
- 2021-02-17
- Publication Date
- 2026-05-22
AI Technical Summary
Existing target delivery systems struggle to reliably count the number of irradiated targets entering or leaving the reactor core, especially when there is lateral vibration and rotation between targets in the target queue. Existing sensor devices cannot accurately identify the geometric contours of multiple targets or the gaps between carriers.
At least two distance sensors are arranged along the circumference of the pipe at a constant angular spacing to measure the radial distance between the target and the sensor. The number of targets is determined by calculating intermediate signals and pattern recognition algorithms, including edge detection and deconvolution algorithms, to improve counting accuracy.
It enables accurate and reliable counting of the number of targets under high speed and target queue contact conditions, improving the counting accuracy and reliability of the target delivery system.
Smart Images
Figure CN116848591B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a target delivery system for a radionuclide generation system. Background Technology
[0002] Radionuclides are used in various fields of technology and science, as well as for medical purposes. Typically, radionuclides are produced in research reactors or cyclotrons. Because the number of facilities for commercial production of radionuclides is limited and expected to decrease, alternative production sites are needed.
[0003] Commercial nuclear reactors can be used to produce radionuclides. In particular, conventional aero-ball measurement systems or other instrumentation systems in commercial reactors can be modified and supplemented to enable efficient and effective production of radionuclides. For example, some instrumentation tubes in commercial aero-ball measurement systems or through-core probe (TIP) systems are used to introduce an irradiated target into the reactor core and to extract the activated irradiated target from the reactor core. Target activation is optimized by positioning the irradiated target in a predetermined region of the reactor core, said region having a neutron flux sufficient to completely convert the parent material in the irradiated target into the desired radionuclide.
[0004] For example, WO2017 / 012655A describes a radionuclide generation system comprising:
[0005] An instrumentation system for a nuclear reactor, comprising at least one instrument finger extending into the reactor core, wherein the instrumentation system is configured to allow insertion and removal of an irradiation target into and from the instrument finger; and
[0006] A target drive system comprising a piping system and configured to insert an irradiated target into an instrument finger and remove the irradiated target from the instrument finger in a predetermined linear sequence.
[0007] Target-driven systems are typically pneumatically operated, meaning that pressurized gas is driven through the piping system of the target-driven system to move the irradiated target from one location to another within the radionuclide generation system.
[0008] When operating a radionuclide generation system, it is important to be able to count the targets entering and leaving the reactor core to ensure that all targets entering the core also leave the core.
[0009] However, the sensor described in WO2017 / 012655A is not entirely satisfactory.
[0010] In fact, due to pneumatic drive, most targets are typically moved as a target queue through the pipes of the delivery system, where the targets are in contact with each other at their axial ends.
[0011] The inventors of this invention have discovered that existing sensor devices, which include a sensor at each counting position, cannot reliably count targets in such a target queue. In fact, these targets vibrate and rotate laterally within the pipe, i.e., move perpendicular to their primary direction of movement through the pipe. This makes it difficult for existing systems to identify multiple targets that are very close to each other, as it is impossible to resolve their geometric contours or the gaps between the carriers. Summary of the Invention
[0012] Therefore, one object of the present invention is to provide a target delivery system for a radionuclide generation system that can accurately and reliably count the number of targets entering or leaving the reactor core.
[0013] For this purpose, the present invention relates to a target delivery system for a radionuclide generation system, the target delivery system comprising:
[0014] - Pipelines used to transport irradiated targets through a radionuclide generation system;
[0015] - A target drive system configured to drive an irradiated target through the pipe;
[0016] - A counting system configured to count the number of irradiated targets passing through the pipe.
[0017] The counting system includes at least two distance sensors, each configured to measure the radial distance between the distance sensor and the irradiation target. The distance sensors are arranged at the same axial position along the pipe and regularly spaced apart at a constant angular pitch along the circumference of the pipe.
[0018] The target delivery system may also include one or more of the following features, individually or in any technically possible combination:
[0019] - The distance sensor is an inductive sensor, particularly an eddy current sensor;
[0020] The target delivery system also includes a sensor support mounted on the pipeline, with distance sensors mounted on the sensor support such that for each distance sensor, there is no obstruction to the sensor signal between the distance sensor and the interior of the pipeline;
[0021] - The target delivery system also includes a calculator configured to perform the following method steps:
[0022] - Receive distance signals obtained from the distance sensor;
[0023] - Calculate an intermediate signal whose amplitude depends on the sum of distance signals from the distance sensors; and
[0024] - The number of irradiated targets passing through the pipeline is determined based on intermediate signals;
[0025] - The step of calculating the intermediate signal includes summing the distance signals from the distance sensor, and the intermediate signal corresponds in particular to or is proportional to the sum of the distance signals from the distance sensor;
[0026] - Determining the number of irradiated targets passing through the pipeline involves applying pattern recognition algorithms to intermediate signals;
[0027] - Pattern recognition algorithms are edge detection algorithms;
[0028] - Applications of edge detection algorithms include using comparators to transform intermediate signals into final binary signals;
[0029] - The step of determining the number of irradiated targets passing through the pipe also includes counting the number of irradiated targets based on the final binary signal, in particular by counting pulses in the final signal with a width greater than or equal to a predetermined threshold;
[0030] The method also includes the step of applying a deconvolution algorithm to the intermediate signal before applying the pattern recognition algorithm; and
[0031] The counting system includes exactly two distance sensors at a given axial position along the pipe, the distance sensors facing each other along the radial direction of the pipe.
[0032] The present invention also relates to a radionuclide generation system comprising a target delivery system as described above, the target delivery system being configured to insert an irradiated target into a predetermined position in the core of a nuclear reactor in a predetermined linear sequence.
[0033] The radionuclide generation system may also include one or more of the following features, either individually or in any technically possible combination:
[0034] - The radionuclide generation system also includes at least one guide tube extending into the core of the nuclear reactor, and the target delivery system is configured to insert the irradiated target into the guide tube in a predetermined linear sequence;
[0035] - A nuclear reactor is a heavy water reactor.
[0036] The present invention also relates to a method for counting irradiated targets passing through a conduit in a radionuclide generation system using a target delivery system, the method comprising the following steps:
[0037] - Receive distance signals from the distance sensor;
[0038] - Calculate an intermediate signal whose amplitude depends on the sum of distance signals from the distance sensors; and
[0039] - The number of irradiated targets passing through the pipeline is determined based on the intermediate signal.
[0040] The method may also include one or more of the following features, either individually or in any technically possible combination:
[0041] - Determining the number of irradiated targets passing through the pipeline involves applying pattern recognition algorithms to intermediate signals;
[0042] - Pattern recognition algorithms are edge detection algorithms; and
[0043] The step of calculating the intermediate signal involves summing the distance signals from the distance sensor, and the intermediate signal corresponds in particular to or is proportional to the sum of the distance signals from the distance sensor. Attached Figure Description
[0044] The invention will be better understood by reading the following description, which is given by way of example only and with reference to the accompanying drawings, in which:
[0045] - Figure 1 It is a schematic cross-sectional view of a portion of the target delivery system according to the first embodiment, taken along a plane parallel to the axis of the pipe.
[0046] - Figure 2 It is a schematic cross-sectional view of a portion of the target delivery system according to the first embodiment, taken along a plane perpendicular to the axis of the pipe;
[0047] - Figure 3 This is a 3D view of the sensor support component;
[0048] - Figure 4 It is a cross-sectional view of the sensor support taken along a plane parallel to the axis of the pipe;
[0049] - Figure 5 This is a schematic diagram of the target counting method according to the present invention;
[0050] - Figure 6 This is a graph showing the signal obtained when performing a target counting method according to an example; and
[0051] - Figure 7 It is a part of the target delivery system according to the second embodiment, similar to Figure 2 The view. Detailed Implementation
[0052] This invention relates to a target delivery system 1 for a radionuclide generation system. The radionuclide generation system is intended for use in nuclear reactors to produce activated irradiated targets.
[0053] The target delivery system 1 is located specifically in the nuclear reactor, for example, at least partially in the reactor core.
[0054] like Figure 1 and Figure 2 As shown, the target delivery system 1 includes:
[0055] - Pipeline 5, which is used to transport the irradiated target 7 through the radionuclide generation system;
[0056] - Target drive system 9, which is configured to drive the irradiated target 7 through the pipe 5;
[0057] - Counting system 12, which is configured to count the number of irradiated targets 7 passing through pipe 5.
[0058] Pipe 5 has a central axis A, which defines the axial direction of pipe 5. Pipe 5 has, for example, a circular cross-section.
[0059] The target drive system 9 is advantageously pneumatically operated and uses, for example, a pressurized gas such as nitrogen or air to drive the irradiation target 7 through the conduit 5. The target drive system 9 includes, for example, a pressurized gas source.
[0060] Preferably, the target drive system 9 includes one or more pneumatically operated valve assemblies (not shown) for individually controlling the insertion and delivery of the irradiated target 7 through the conduit 5. Furthermore, the target drive system 9 may also include a gate system (not shown) comprising several mechanical and / or electromechanical devices configured to guide the irradiated target 7 into selected guide tubes in the reactor core, such as into selected conduits of the instrumentation system and instrument pointers within the reactor core.
[0061] The counting system 12 includes at least two distance sensors 15, each configured to measure a radial distance d1 or d2 between the distance sensor 15 and the irradiated target 7. In this document, "radial distance" is measured along the radius of the pipe 5. The distance sensors 15 output distance signals s1(t) and s2(t), respectively.
[0062] The distance sensor 15 is preferably an inductive sensor, such as an eddy current sensor. Inductive sensors can withstand high radiation doses, and their output signals are unaffected by radiation from the passing irradiation target 15. The signal output of each inductive sensor is proportional to the distance between the sensor and the irradiation target 7. The cutoff frequency of the distance sensor 15 is selected based on the geometry and displacement velocity of the irradiation target 7. For example, it is equal to 20 kHz. The sampling rate is, for example, greater than or equal to 20 kilosamples / s.
[0063] The sensing sensor is preferably an analog sensor.
[0064] At least two distance sensors 15 are arranged at the same axial position along the pipe 5. They are regularly spaced apart at a constant angular spacing along the circumference of the pipe 5.
[0065] More specifically, in Figures 1 to 4 In the target delivery system 1 according to the first embodiment, shown more specifically, the counting system 12 includes exactly two distance sensors 15 at a given axial position along the pipe 5, these distance sensors 15 facing each other in the radial direction of the pipe 5. The two distance sensors 15 are spaced 180° apart from each other. They are arranged along the same axis.
[0066] Two distance sensors 15 are arranged symmetrically with respect to the midplane of the pipe 5, which passes through the central axis of the pipe 5.
[0067] Each distance sensor 15 operates at a different carrier frequency than the other distance sensors 15 to avoid interference.
[0068] like Figure 1 As shown, the counting system 12, and more specifically the distance sensor 15, is preferably arranged in the straight section of the pipe 5.
[0069] The target drive system 9 is specifically configured to drive the irradiated target 7 through the pipe 5, so that the irradiated target 7 passes in front of the distance sensor 15 at a constant speed.
[0070] exist Figures 1 to 4 In the illustrated embodiment, the target delivery system 1 further includes a sensor support 18 mounted on the pipe 5. For simplicity of the drawings, Figure 1 and Figure 2 The sensor support 18 is not shown in the image.
[0071] In this example, the distance sensor 15 is mounted on the sensor support 18 such that there are no obstructions between the distance sensor 15 and the interior of the pipe 5 for sensor measurement. In this context, an obstruction for sensor measurement is an obstacle that alters the sensor signal, such as an obstacle made of metallic material. Specifically, no part of the pipe 5 extends radially between the distance sensor 15 and the interior of the pipe 5.
[0072] The sensor support 18 is specifically configured to be pressure sealed.
[0073] Figure 3 and Figure 4 A sensor support 18 according to an example is shown in more detail. In this example, the sensor support 18 includes a central body 20 that defines a central axial channel 22 intended for the passage of an irradiation target 7. More specifically, as Figure 4As shown, pipe 5 is interrupted at sensor support 18 and extends on both sides of sensor support 18 in its axial direction. The central axis A of pipe 5 is aligned with the central axis D of central axial channel 22.
[0074] The central channel 22 has, for example, a circular cross-section.
[0075] For each distance sensor 15, the central body 20 also includes a through-hole 24 designed for receiving the distance sensor 15. The through-hole 24 extends through the central body 20 and leads to the central axial channel 22. Figure 3 and Figure 4 In the example shown, the sensor support 18 includes two through holes 24 facing each other across the central axial channel 22. Each distance sensor 15 is arranged in a corresponding through hole 24 to enable the measurement of the radial distance between the distance sensor 15 and the irradiation target 7 passing through the central axial channel 22. Figure 4 In the example shown, the diameter of the central axial channel 22 is constant from one axial end 28 of the central body 20 to the other axial end. The diameter of the central axial channel 22 is specifically equal to the inner diameter of the pipe 5.
[0076] Optionally, the sensor support 18 also includes a tubular insert (not shown) disposed in front of the distance sensor 15 in the insertion through-hole 24. The inner diameter of the tubular insert is approximately equal to the inner diameter of the pipe 5. The tubular insert is made of a material that does not affect the measurement of the distance sensor 15, and is particularly made of a synthetic material, such as plastic, especially PEEK (polyetheretherketone). The purpose of this tubular insert is to protect the surface of the distance sensor and prevent the irradiation target 7 from colliding with the edge of the sensor support 18.
[0077] The sensor support 18 also includes fittings 26 at each axial end 28 of the central body 20, the fittings 26 being configured for mounting the sensor support 18 to the pipe 5. More specifically, in Figure 4 In the example shown where pipe 5 is interrupted at sensor support 18, each fitting 26 is mounted on the corresponding end of pipe 5.
[0078] Accessory 26 is connected to the central body 20 and pipe 5 in a fluid-tight manner, for example, by means of a suitable sealing gasket. Figure 4 In the example shown, the central body 20 includes an enlarged portion 30 at each of its axial ends 28, which defines a seat 32 for receiving the fitting 26 in a fluid-tight manner.
[0079] The distance sensor 15 is advantageously mounted on the sensor support 18 so that it can be displaced in the radial direction relative to the sensor support 18. This possibility of displacement allows the position of the distance sensor 15 to be adjusted in the radial direction.
[0080] Advantageously, the sensor support 18 includes a displacement device configured to displace the distance sensor 15 in a radial direction. Figure 4 In the example shown, these displacement devices include, for example, a piston 34 connected to a distance sensor 15 via a corresponding thread, and a piston cap 36 disposed on a central body 20 and defining a piston chamber extending around a through-hole 24. The piston 34 is movable radially relative to the central body 20 within the piston chamber, which causes the distance sensor 15 to be displaced radially.
[0081] The central body 20 is advantageously made of metal, including steel (e.g., stainless steel) and / or aluminum.
[0082] According to the invention, the delivery system 1 also includes a calculator 40, such as a computer. The calculator 40 specifically includes a processor 42, a memory 44, and a media reader 46.
[0083] In this example, the calculator 40 interacts with a computer program product containing program instructions to be executed by the processor 42. The computer program product is stored on a data carrier.
[0084] A data carrier is a medium that can be read by the computer 40, typically by the processor 42, via a media reader 46. A readable data carrier is a medium suitable for storing instructions and capable of being coupled to the bus of a computer system. For example, readable data media include floppy disks, optical disks, CD-ROMs, magneto-optical disks, ROMs, RAM memories, EPROM memories, EEPROM memories, magnetic cards, optical cards, USB flash drives, or SSDs.
[0085] The computer program product can be loaded by the processor 42 of the calculator 40, and is adapted to implement the target counting method according to the invention when the computer program is run on the processor 42. The target counting method will be described in detail below.
[0086] In the second example, the computer 40 includes one or more programmable logic components, such as FPGA (Field Programmable Gate Array), or application-specific integrated circuits, such as ASIC (Application-Specific Integrated Circuit), adapted to perform the target counting method according to the invention.
[0087] In the third example, the computer 40 includes a central processing unit (CPU) and a graphics processing unit (GPU) adapted to perform the target counting method according to the invention, wherein the GPU acts as a coprocessor.
[0088] Now refer to Figure 5 and Figure 6 The target counting method according to the present invention is described.
[0089] Figure 6The distance signals s1(t) and s2(t) shown in the graph correspond to the distance signals obtained when using the target delivery system 1 according to the first embodiment of the invention, wherein the counting system 12 includes exactly two distance sensors 15 at the considered axial positions along the pipe 5. Furthermore, the distance signals s1(t) and s2(t) are obtained during the passage of the 12 irradiated targets 7 through the pipe 5.
[0090] In the first step 100 of the method, the calculator 40 receives distance signals s1(t) and s2(t) acquired by the distance sensor 15 during the passage of the irradiated target 7. The distance signals s1(t) and s2(t) correspond to, or are proportional to, the radial distances d1 and d2 between the irradiated target 7 and the corresponding distance sensor 15 as a function of time. These distance signals s1(t) and s2(t) in... Figure 6 As shown in the figure, the distance signals s1(t) and s2(t) have chaotic components, which are caused by the movement of the irradiated target 7 perpendicular to the axial direction, either away from or towards the distance sensor 15. Due to this chaotic component, it is impossible to reliably detect the passage of the irradiated target 7 in front of the distance sensor 15 based solely on the distance measurement obtained by the distance sensor 15.
[0091] According to the present invention, in the second step 102, the calculator 40 calculates the intermediate signal s based on the distance signals s1(t) and s2(t). int (t). More specifically, the intermediate signal s int The amplitude of (t) is linearly related to the sum of the distance signals s1(t) and s2(t) obtained by the distance sensor 15, and is, for example, proportional to or equal to the sum of the distance signals s1(t) and s2(t) obtained by the distance sensor 15. Intermediate signal s int The amplitude of (t) is linearly related to the diameter distribution of the irradiated target 7 passing through pipe 5. In this paper, the diameter distribution of the irradiated target 7 corresponds to the diameter of the irradiated target 7 as a function of the distance from one end of the target 7. Since the irradiated target 7 passes through the distance sensor 15 at a constant speed, this diameter distribution can also be expressed as a function of time.
[0092] In a first embodiment of the invention, in which the counting system 12 includes exactly two distance sensors 15 at a given axial position along the pipe 5, the second step 102 advantageously includes summing the distance signals s1(t) and s2(t) from the two distance sensors 15. In this embodiment, Figure 6 The intermediate signal s shown int(t) corresponds to the sum of the two distance signals s1(t) and s2(t). As can be seen in the figure, the summation of the two distance signals s1(t) and s2(t) removes the chaotic components caused by the movement of the irradiation target 7 in the axial direction perpendicular to the pipe 5.
[0093] In this case, the sum of the distance signals s1(t) and s2(t) is expressed by the following formula relative to the diameter distribution d of the irradiated target 7. 靶 (t) Related: d 靶 (t)=d 管道 -(s1(t)+s2(t)), where d 管道 It is the inner diameter of pipe 5.
[0094] In the third step 104, the calculator 40 is based on the intermediate signal s int (t) Determine the number of irradiated targets 7 passing through pipe 5.
[0095] More specifically, determining the number of irradiated targets 7 passing through pipe 5 includes the determination of intermediate signals s. int (t) Applying pattern recognition algorithms.
[0096] Based on the example, the pattern recognition algorithm is an edge detection algorithm.
[0097] More specifically, applications of edge detection algorithms include using comparators, particularly comparators with hysteresis (such as Schmitt triggers), to process intermediate signals s. int (t) is transformed into the final binary signal s f (t).
[0098] In this step, the threshold(s) of the comparator(s) are selected to detect the intermediate signal s corresponding to the irradiated target 7 passing in front of the distance sensor 15. int The value of (t) is a part of (t). The value of (one or more) thresholds depends in particular on the diameter of the irradiated target 7. (One or more) thresholds can be adjusted, for example, by calibration measurement, preferably during the installation phase of the target delivery system 1.
[0099] For example, if the intermediate signal s int If (t) is higher than the comparator threshold, then the final binary signal s f The value of (t) is logical "1".
[0100] In this example, the third step 104 also includes, after applying the edge detection algorithm, based on the final binary signal s f (t) Count the number of irradiated targets 7 that have passed through pipe 5. More specifically, counting the number of irradiated targets 7 that have passed through pipe 5 includes counting the final signal (s) with a width greater than or equal to a predetermined threshold T. fThe pulses in (t) are counted. For example, during this step, the final binary signal s is counted. f (t) A filter is applied to determine the number of peaks with a width greater than a predetermined threshold T. This is achieved by detecting the final binary signal s. f The rising and falling edges of (t) are determined and the time difference between the detected rising and falling edges is determined, or by analyzing the binary signal s. f The pulse width of (t) is calculated using an integrator circuit.
[0101] The predetermined threshold T depends specifically on the length and velocity of the irradiated target 7. For example, for an irradiated target 7 with a length of 7 cm and a velocity of 30 m / s at the distance sensor 15, it takes approximately 2 ms to pass through the sensor 15. Therefore, a threshold T of 1 ms can be chosen to consider that the target has not passed if the velocity is greater than (7 cm) / 1 ms = 70 m / s. The threshold T is chosen to eliminate specific interference that may couple into the cable of the distance sensor 15.
[0102] Advantageously, the irradiated target 7 has specific geometric features, such as diameter variations, which helps to distinguish intermediate signals s by applying an edge detection algorithm with an appropriate threshold T. int Each of the irradiated targets 7 in (t). For example, Figure 1 The irradiation target 7 shown has an end cap 51 at its axial end 50, the end cap 51 having a geometry including a diameter variation. More specifically, the end cap 51 includes a segment 53 at its axial end with a diameter smaller than the rest of the irradiation target 7. This smaller diameter end segment 53 results in an intermediate signal s between the two irradiation targets 7. int The decrease in (t) makes it possible to distinguish the irradiated target 7 by applying an edge detection algorithm. Figure 1 In the example shown, the end cap 51 also includes a segment 54 adjacent to the small-diameter end segment 53, which has a diameter larger than the rest of the irradiated target 7.
[0103] Other examples of pattern recognition algorithms that can be used in step 104 are peak detection, template matching, or any other adapted pattern recognition algorithm known, for example, from image processing.
[0104] Optionally, the calculator 40 performs a test on the intermediate signal s before applying the pattern recognition algorithm and, for example, before applying the edge detection algorithm described above. int (t) Applying the deconvolution algorithm. More specifically, the deconvolution algorithm uses the sensor's sensitivity distribution s(x) to estimate the original geometric distribution of the irradiated target 7. This eliminates the influence of the sensor sensitivity distribution s(x), thus improving the resolution of the geometric distribution approximation of the target array. In fact, the intermediate signal s int(t) is generated by the convolution of two functions: the geometric distribution g(x) of the target queue and the sensitivity distribution s(x) of the sensor, divided by the velocity of the irradiated target 7 passing through.
[0105] The sensitivity distribution s(x) of a sensor can be stored on a data carrier. For example, it can be determined through testing.
[0106] The signal processing involved in steps 100, 102, and 104 above is performed, for example, by a computer program product stored on a readable data carrier and executed by processor 42.
[0107] According to an alternative approach, the signal processing involved in steps 100, 102, and 104 is performed using adapted analog circuitry known to those skilled in the art. For example, step 104 can be performed using analog circuitry including flip-flops.
[0108] Figure 7 A target delivery system 100 according to a second embodiment is shown. In the description of this embodiment, the same reference numerals are used to denote elements already described with respect to the first embodiment.
[0109] The target delivery system 100 according to the second embodiment differs from the target delivery system 1 according to the first embodiment only in that the counting system 9 includes three distance sensors 15 at the axial position along the conduit 5, instead of two.
[0110] Three distance sensors 15 are regularly spaced along the circumference of the pipe 5 at a constant angular spacing. More specifically, in this embodiment, the angle between adjacent distance sensors 15 is equal to 120°.
[0111] In this embodiment, the sum of distance signals s1(t), s2(t), and s3(t) is expressed by the following formula relative to the diameter distribution d of the irradiated target 7 passing through pipe 5. 靶 (t) Related:
[0112]
[0113] in:
[0114] d 靶 (t) represents the diameter distribution of the irradiated target 7 through pipe 5.
[0115] d is the diameter of pipe 5, and
[0116] s1(t), s2(t), and s3(t) are distance signals obtained by three distance sensors 15.
[0117] The method associated with the target counting system 100 according to the third embodiment differs from the method according to the first embodiment described above only in that, in step 102, the intermediate signal s int (t) corresponds to the sum of the three distance signals s1(t), s2(t), and s3(t) obtained by the three distance sensors 15.
[0118] The target counting system according to the third embodiment (not shown) differs from the target counting system 1 according to the first embodiment only in that the number of distance sensors 15 at a given axial position along the pipe 5 is equal to n, where n is greater than three, and the n distance sensors 15 are regularly spaced apart along the circumference of the pipe 5 at a constant angular spacing. In this case, the angle between adjacent distance sensors is equal to n is, for example, less than or equal to 6.
[0119] In this embodiment, the distance signals s1(t), s2(t), ..., s n The sum of (t) is expressed by the following formula in relation to the diameter distribution d of the irradiated target 7 through pipe 5. 靶 (t) Related:
[0120]
[0121] in:
[0122] d 靶 (t) represents the diameter distribution of the irradiated target 7 through pipe 5.
[0123] d is the diameter of pipe 5.
[0124] s i (t) is the distance signal obtained by distance sensor 15.
[0125] The method associated with the target counting system according to the third embodiment differs from the method according to the first embodiment described above only in that, in step 102, the intermediate signal s int (t) and n distance signals s1(t), s2(t), ..., s2(t) obtained by n distance sensors 15 n The sum of (t) corresponds to this.
[0126] The accuracy of the target counting system 12 increases with the number of distance sensors 15. However, the accuracy obtained using two distance sensors 15 as described in the first embodiment is sufficient for most applications.
[0127] The counting system according to the invention is advantageous because it allows for the counting of the number of irradiated targets 7 entering or leaving the nuclear reactor core in a particularly accurate and reliable manner, even at relatively high target velocities (e.g., greater than 10 m / s) and in the case of direct contact between the irradiated targets 7 and the target queue in the conduit 5.
[0128] The present invention also relates to a radionuclide generation system comprising a target delivery system 1; 100 as described above, the target delivery system 1; 100 being configured to insert an irradiated target 7 into a predetermined position in a nuclear reactor core in a predetermined linear sequence.
[0129] The radionuclide generation system more specifically includes at least one guide tube extending into the reactor core, and the target delivery system 1, 100 is configured to insert the irradiated target 7 into the guide tube in a predetermined linear sequence.
[0130] According to one embodiment, the nuclear reactor is a heavy water reactor, such as a CANDU (Canadian deuterium-uranium) type heavy water reactor. In this case, the guide tube is, for example, a guide tube inserted into a port in the reactive structure deck of the heavy water reactor, as described in, for example, in earlier application WO2016 / 207054A1.
[0131] According to the alternative, the nuclear reactor is a light water reactor, such as a pressurized water reactor. In this case, the guide tube is, for example, an instrumentation device for the nuclear reactor, as described in, for example, in prior application WO2017 / 012655A1.
[0132] Such systems are known to those skilled in the art and are not described in detail in this patent application.
[0133] The irradiated target 7 used in the above-described radionuclide generation system and target counting method specifically includes a casing that encapsulates a core made of non-fissile material and includes suitable precursor materials for generating radionuclides to be used for medical and / or other purposes.
[0134] The envelope has a rotationally symmetric shape, such as a circular cross-section.
[0135] The envelope hermetically seals the reactor core. For example, it is made of a material with low neutron flux, such as polyetheretherketone (PEEK). The envelope may preferably include portions made of metallic materials to allow for improved detection, such as the use of inductive sensors.
[0136] The reactor core specifically contains precursor materials in powder form.
[0137] More preferably, the irradiation target 7 is composed of a precursor material that is converted into the desired radionuclide upon activation by exposure to the neutron flux present in the reactor core of an operating commercial nuclear reactor. Useful precursor materials are Mo-98, Yb-176, and Lu-176, which are converted into Mo-99 and Lu-177, respectively. However, it should be understood that the invention is not limited to the use of specific precursor materials.
[0138] As shown above (refer to the reference) Figure 1 According to a specific example, the envelope includes an end cap 51 at the axial end 50 of the irradiation target 7, and the end cap 51 includes a segment 53 at its axial end with a diameter smaller than the rest of the irradiation target 7. Figure 1 In the example shown, the end cap 51 also includes a segment 54 adjacent to the small-diameter end segment 53, which has a diameter larger than the rest of the irradiated target 7.
Claims
1. A target delivery system for a radionuclide generation system, the target delivery system comprising: - Pipe (5), which is used to transport the irradiated target (7) through the radionuclide generation system; - Target drive system (9), which is configured to drive the irradiated target (7) through the pipe (5); - A counting system (12) configured to count the number of irradiated targets (7) passing through the pipe (5); Its features are, The counting system (12) includes at least two distance sensors (15), each distance sensor being configured to measure the radial distance (d1, d2) between the distance sensor (15) and the irradiation target (7). The distance sensors (15) are arranged at the same axial position along the pipe (5) and are regularly spaced apart at a constant angular spacing along the circumference of the pipe (5).
2. The conveying system according to claim 1, wherein the distance sensor (15) is an inductive sensor.
3. The conveying system according to claim 1 or 2, further comprising a sensor support (18) mounted on the pipe (5), wherein the distance sensor (15) is mounted on the sensor support (18) such that for each distance sensor (15), there is no obstruction of sensor signal between the distance sensor (15) and the interior of the pipe (5).
4. The conveying system according to claim 1 or 2, further comprising a calculator (40) configured to perform the following method steps: - Receive distance signals (s1(t), s2(t); s1(t), s2(t), s3(t)) obtained by the distance sensor (15); - Calculate intermediate signals (s) int (t)), the intermediate signal (s) int The amplitude of (t) depends on the sum of the distance signals (s1(t), s2(t); s1(t), s2(t), s3(t)) from the distance sensor (15); and - Based on the intermediate signal (s) int (t) determines the number of irradiated targets (7) passing through the pipe (5).
5. The conveying system according to claim 4, wherein the intermediate signal (s) is calculated. int The step of (t) includes summing the distance signals (s1(t), s2(t); s1(t), s2(t), s3(t)) from the distance sensor (15).
6. The conveying system according to claim 4, wherein the intermediate signal (s) int (t) corresponds to or is proportional to the sum of the distance signals (s1(t), s2(t); s1(t), s2(t), s3(t)) from the distance sensor (15).
7. The delivery system according to claim 4, wherein determining the number of irradiated targets (7) passing through the conduit (5) includes determining the intermediate signal (s) int (t) Applying pattern recognition algorithms.
8. The conveying system according to claim 7, wherein the pattern recognition algorithm is an edge detection algorithm.
9. The conveying system of claim 8, wherein the application of the edge detection algorithm includes applying a comparator to the intermediate signal (s) int (t) is transformed into the final binary signal (s) f (t)).
10. The delivery system according to claim 9, wherein the step of determining the number of irradiated targets (7) passing through the conduit (5) further comprises based on the final binary signal (s) f (t) counts the number of irradiated targets (7).
11. The conveying system of claim 7, wherein the method steps further include processing the intermediate signal (s) before applying the pattern recognition algorithm. int (t) The steps of applying the deconvolution algorithm.
12. The conveying system according to claim 1 or 2, wherein the counting system (12) includes exactly two distance sensors (15) at a given axial position along the pipe (5), the distance sensors (15) facing each other in the radial direction along the pipe (5).
13. A radionuclide generation system comprising a target delivery system according to claim 1 or 2, the target delivery system being configured to insert the irradiated target (7) into a predetermined position in the core of a nuclear reactor in a predetermined linear sequence.
14. The radionuclide generation system of claim 13, further comprising at least one guide tube extending into the core of the nuclear reactor, the target delivery system being configured to insert the irradiated target (7) into the guide tube in a predetermined linear sequence.
15. The radionuclide generation system according to claim 13, wherein the nuclear reactor is a heavy water reactor.
16. A method for counting an irradiated target (7) passing through a conduit (5) in a radionuclide generation system using a target delivery system according to claim 4, the method comprising the steps of: - Receive the distance signals (s1(t), s2(t); s1(t), s2(t), s3(t)) from the distance sensor (15); - Calculate intermediate signals (s) int (t)), the intermediate signal (s) int The amplitude of (t) depends on the sum of the distance signals (s1(t), s2(t); s1(t), s2(t), s3(t)) from the distance sensor (15); as well as - Based on the intermediate signal (s) int (t) determines the number of irradiated targets (7) passing through the pipe (5).
17. The method of claim 16, wherein determining the number of irradiated targets (7) passing through the conduit (5) includes determining the intermediate signal (s) int (t) Applying pattern recognition algorithms.
18. The method according to claim 17, wherein the pattern recognition algorithm is an edge detection algorithm.
19. The method of claim 16, wherein the intermediate signal (s) is calculated. int The step of (t) includes summing the distance signals (s1(t), s2(t); s1(t), s2(t), s3(t)) from the distance sensor (15).