High temperature gas cooled reactor in-situ irradiation device, arrangement thereof and in-situ irradiation method

Abstract

The application discloses a high-temperature gas cooled reactor online irradiation device, arrangement and online irradiation method, and belongs to the technical field of nuclear energy utilization. The device comprises three neutron source holes, an online irradiation device body and an integrated assembly. The neutron source holes are arranged at 30 degrees, 150 degrees and 270 degrees of a reactor pressure vessel head cover respectively. A connecting pipeline is arranged in each neutron source hole. The online irradiation device body is arranged in a reactor maintenance hall and is communicated with the connecting pipeline. The other end of the connecting pipeline extends to an active region of the reactor. The integrated assembly is arranged in the connecting pipeline and is close to the irradiation section of the active region. The integrated assembly comprises a moderation module, a reflection module and an axial sliding mechanism. The integrated assemblies in the three neutron source holes are independent of each other. The axial sliding mechanism is used for independently regulating and controlling the neutron spectrum and the neutron flux of each hole. The application further provides a corresponding arrangement and online irradiation method. The application can realize parallel and collaborative irradiation production of multiple kinds of isotopes in the same reactor operation cycle.

Description

Technical Field

[0001] This invention relates to an online irradiation device for a high-temperature gas-cooled reactor, its arrangement, and an online irradiation method, belonging to the field of nuclear energy utilization technology. Background Technology

[0002] Isotopes have important applications in many fields such as nuclear energy, environmental protection, medicine, geological exploration, and materials science.

[0003] Compared to some conventional reactors, high-temperature gas-cooled reactors have a neutron flux several times higher, enabling target materials to undergo nuclear reactions more effectively and improving the production efficiency and yield of isotopes.

[0004] However, existing high-temperature gas-cooled reactors rely solely on the inherent neutron field within the reactor core for irradiation of their neutron source channels. Consequently, the neutron energy spectra and fluxes of multiple channels within the same reactor tend to be uniform, making differentiated control between different channels impossible. Furthermore, because isotopes such as molybdenum-99, iodine-123, technetium-99m, and cobalt-60 have different nuclear reaction thresholds and optimal neutron energy spectrum requirements, the single-energy-spectrum irradiation environment limits the parallel and coordinated production of multiple isotopes within the same reactor phase. This results in low reactor irradiation capacity utilization, making it difficult to meet the ever-increasing market demand. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides an online irradiation device for a high-temperature gas-cooled reactor, its arrangement, and an online irradiation method, achieving a uniform and stable neutron flux distribution at the three irradiation sites.

[0006] The technical solution of the present invention is as follows: An online irradiation device for a high-temperature gas-cooled reactor includes three neutron source channels, an online irradiation device body, and integrated components. The neutron source channels are respectively located at 30°, 150°, and 270° angles on the top cover of the high-temperature gas-cooled reactor pressure vessel. Each neutron source channel is provided with a connecting pipe. The online irradiation device body is located in the reactor maintenance hall and is connected to the connecting pipe. The other end of the connecting pipe extends to the reactor active area. The integrated components are nested inside the connecting pipe near the irradiation section of the reactor active area. The integrated components include a moderation module, a reflection module, and an axial sliding mechanism. The integrated components in the three neutron source channels are independent of each other. The axial coverage height of the moderation module and the reflection module is adjusted by the axial sliding mechanism to independently control the neutron energy spectrum and neutron flux inside each neutron source channel.

[0007] The connecting pipes include an upper curved conduit and a lower straight conduit. The upper curved conduit is angled to match the pressure vessel top cover, and the lower straight conduit extends vertically to the reactor active area. The online irradiation device integrates a target dynamic positioning system, which includes an embedded isotope type database and infrared positioning sensors spaced along the axial direction of the lower straight conduit. The embedded isotope type database pre-stores the irradiation duration and temperature and pressure thresholds for molybdenum-99 and iodine-123. The infrared positioning sensors collect the isotope target position signals in real time and feed them back to the control system, achieving a positioning accuracy of ±2mm to ensure that the isotope target is in the neutron flux peak region.

[0008] The online irradiation device also integrates a distributed leakage early warning system, which includes radioactive leakage monitoring sensors arranged at both ends and intermediate nodes of the connecting pipeline. When any radioactive leakage monitoring sensor detects a radiation dose rate ≥0.1μSv / h, it triggers a local early warning, suspends the transfer of isotope targets, and locks the corresponding neutron source channel.

[0009] The online irradiation device and connecting pipes are equipped with a graded radiation protection structure along the axis. The graded radiation protection structure includes a lead alloy shielding layer installed at the outlet section of the channel near the reactor active area and a lead alloy and carbon fiber composite shielding layer installed on the side of the reactor maintenance hall away from the reactor active area.

[0010] The moderating module adopts a composite layered structure of graphite and zirconium hydride; the reflecting module adopts a composite structure of beryllium alloy and stainless steel reflecting layer; the integrated component is also equipped with a neutron energy spectrum flux monitoring probe, which is used to collect neutron parameters of each neutron source channel in real time and feed them back to the axial sliding mechanism in a closed loop.

[0011] The adaptive adjustment mechanism for the duct axis is located at the connection between the upper curved guide tube and the lower straight guide tube. The adaptive adjustment mechanism for the duct axis includes an electric actuator and a displacement sensor, which can compensate for an installation error of ±3°, so that the axial deviation between the upper curved guide tube and the lower straight guide tube after correction is ≤0.3mm.

[0012] Each neutron source channel is equipped with a built-in neutron flux monitoring probe and an energy spectrum monitoring probe. The neutron flux monitoring probe and the energy spectrum monitoring probe are connected to the control system to form a closed-loop control, and the component position formula corresponding to different isotope targets is preset.

[0013] An arrangement and online irradiation method for a high-temperature gas-cooled reactor-based online irradiation device, characterized by comprising the following steps: S1: Based on the reactor's geometric symmetry, three neutron source channels with angles of 30°, 150°, and 270° are selected on the pressure vessel top cover, and connecting pipes and integrated components are installed inside the neutron source channels; S2: Fix the online irradiation device in the reactor maintenance hall and connect it to three neutron source channels through connecting pipes to debug the target dynamic positioning system, graded radiation protection structure and distributed leakage early warning system; S3: Coaxially nested integrated components are installed inside the active region of the lower straight guide tube of each neutron source channel to perform initial in-pile calibration and solidify the energy spectrum reference for three working conditions: thermal neutron enrichment, resonant neutron adaptation, and fast neutron enhancement. S4: The isotope target is loaded into the inlet of the online irradiation device and sent down to the reactor active area for irradiation through the connecting pipe. The target is then positioned by the target dynamic positioning system and removed in the reverse direction after irradiation is completed.

[0014] Specifically, the embedded isotope type database is called to match the optimal irradiation time, temperature threshold, and pressure threshold of the current isotope target; when the irradiation time of the isotope target reaches the preset time, the isotope target removal command is triggered, driving the conveying mechanism to lift the target to the device inlet in the reverse direction.

[0015] Among them, the first neutron source channel was adjusted to the thermal neutron energy spectrum enrichment mode; the second neutron source channel was adjusted to the resonant neutron energy spectrum mode; and the third neutron source channel was adjusted to the fast neutron flux enhancement mode.

[0016] The present invention has the following beneficial effects: This invention achieves uniform and stable neutron flux distribution at the three irradiation sites by setting three neutron source channels at angles of 30°, 150° and 270° on the top cover of the reactor pressure vessel, forming an equally spaced and symmetrical distribution.

[0017] This invention achieves independent control of the neutron energy spectrum and neutron flux in each channel by setting an integrated component containing a moderation module, a reflection module and an axial sliding mechanism inside the connecting pipe of each neutron source channel, and by making the integrated components of the three channels independently adjustable.

[0018] This invention achieves precise positioning of isotope targets in the neutron flux peak region by setting up a target dynamic positioning system, including an embedded isotope type database and infrared positioning sensors arranged at intervals along the lower straight conduit axis, thereby reducing the loss of product activity caused by irradiation position deviation.

[0019] This invention establishes a distributed leak early warning system, which deploys radioactive leak monitoring sensors at both ends and intermediate nodes of the connecting pipeline. When a radiation dose rate ≥0.1μSv / h is detected, an early warning is triggered, the transfer is suspended, and the corresponding channel is locked, thus achieving early detection and rapid isolation of radioactive leaks.

[0020] This invention achieves differentiated protection configurations based on radiation levels in different areas by setting up a graded radiation protection structure. A lead alloy shielding layer is used in the outlet section of the channel near the active area, while a composite shielding layer of lead alloy and carbon fiber is used in the maintenance hall side away from the active area. This reduces material costs and structural weight. Attached Figure Description

[0021] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0023] Please see Figure 1 The invention provides a technical solution: An online irradiation device for a high-temperature gas-cooled reactor includes three neutron source channels, an online irradiation device body, and integrated components. The neutron source channels are respectively located at 30°, 150°, and 270° angles on the top cover of the high-temperature gas-cooled reactor pressure vessel. These three angles are symmetrically distributed at 120° intervals on the circumference, fully utilizing the geometric symmetry of the reactor pressure vessel top cover. This not only ensures a uniform and stable neutron flux distribution at the three irradiation sites but also deliberately avoids the channel at the 90° angle, which is typically reserved for other critical reactor systems, thus preventing mutual interference.

[0024] Each of the neutron source channels is provided with a connecting pipe, which consists of an upper curved conduit and a lower straight conduit: the upper curved conduit is adapted to the angle of the pressure vessel top cover to ensure sealing and mechanical cushioning; the lower straight conduit extends vertically to the reactor active area and runs through to the upper part of the discharge port so that the target can be quickly transferred after irradiation.

[0025] The online irradiation device is located in the reactor maintenance hall, which is situated above the reactor pressure vessel compartment. This hall is an operational and maintenance area accessible to personnel during normal reactor operation, and it features comprehensive radiation protection and ample space, facilitating remote control and equipment maintenance. The main body of the online irradiation device passes through the reactor pressure vessel compartment cover plate through three sets of neutron source nozzles and is sealed to the three neutron source channels one by one.

[0026] Inside the irradiation section near the reactor's active zone, on the inner side of the connecting pipe, an integrated assembly is nested. This assembly includes a moderator module, a reflector module, and an axial sliding mechanism, without altering the original channel inner diameter (58 mm) or the target delivery channel (compatible with standardized targets with a diameter of 50-55 mm). The integrated assemblies within the three neutron source channels operate independently. The axial coverage height of the moderator and reflector modules is adjusted via the axial sliding mechanism, thereby independently controlling the neutron energy spectrum and neutron flux within each neutron source channel.

[0027] The moderation module adopts a composite layered structure of graphite and zirconium hydride. By utilizing the excellent moderation properties of graphite and the high hydrogen content of zirconium hydride, efficient neutron moderation can be achieved in a limited radial space. Multiple sets of moderation modules with different thicknesses and ratios are set according to the energy spectrum control requirements to adapt to the switching of various working conditions such as thermal neutrons to resonant neutrons. The reflection module adopts a composite structure of beryllium alloy and stainless steel reflective layer. Beryllium alloy has excellent neutron reflection performance, while stainless steel layer provides structural support and radiation resistance. The combination of the two can effectively reflect leaked neutrons back to the irradiation area and improve the local neutron flux density.

[0028] The integrated component also includes a neutron energy spectrum flux monitoring probe, which is used to collect neutron parameters (such as neutron flux density and energy spectrum distribution) of each neutron source channel in real time, and feed these parameters back to the control system of the axial sliding mechanism in a closed loop. The control system automatically fine-tunes the axial position of the slowing module and the reflection module accordingly to ensure that the neutron environment of each channel is always maintained within the preset operating conditions, thus achieving dynamic self-stabilization.

[0029] In addition, an adaptive adjustment mechanism for the duct axis is installed at the connection between the upper curved conduit and the lower straight conduit. This mechanism includes an electric actuator and a displacement sensor, which can compensate for installation errors within a range of ±3°, so that the axial deviation between the upper curved conduit and the lower straight conduit after correction does not exceed 0.3mm. The purpose of this design is to eliminate the small angular deviations caused by welding, assembly, etc. during on-site installation, ensure the smooth transport of the target part along the duct axis, avoid jamming or wear caused by axis misalignment, and thus improve the long-term operational reliability of the device.

[0030] The online irradiation device integrates a target dynamic positioning system, which includes an embedded isotope type database and infrared positioning sensors arranged at intervals along the axial direction of the lower straight duct. Among them, the embedded isotope type database pre-stores the optimal irradiation duration, temperature threshold and pressure threshold for various isotopes (such as molybdenum-99, iodine-123, etc.). These parameters are pre-calibrated based on the half-life and nuclear reaction cross-section characteristics of different nuclides. Infrared positioning sensors are arranged in groups every 3-4 meters along the axial direction of the lower straight conduit, each group consisting of a transmitter and a receiver. As the isotope target descends along the connecting pipe, the infrared positioning sensors collect the target's position signal in real time and feed it back to the control system. The control system compares this signal with the theoretical target position pre-stored in the database. If the deviation exceeds ±2mm, it is corrected through fine-tuning of the conveying mechanism to ensure that the isotope target is always in the neutron flux peak region. This is particularly critical for short-half-life isotopes, as even a small shift in irradiation position can lead to a decrease in neutron flux, affecting product activity and production efficiency. This system eliminates positioning deviations caused by pipe bending, conveying vibrations, or installation errors. Furthermore, it automatically matches the optimal irradiation station based on the different sensitivities of different isotopes to neutron flux peaks.

[0031] The online irradiation device also integrates a distributed leakage early warning system, which includes six radioactive leakage monitoring sensors, respectively arranged at the device end interface, the passage of the cabin cover plate, and the end interface of the three sets of connecting pipes, that is, one sensor is installed at each end and the middle node of each connecting pipe.

[0032] The reason for choosing the two ends and the middle node of the pipeline as monitoring points is that these locations are critical areas where stress is concentrated, sealing is weak, or there are moving parts in the pipeline, making them most prone to radioactive material leakage. At the same time, the three-point layout can form coverage along the entire length of the pipeline, avoiding the blind spot problem of single-point monitoring.

[0033] When any sensor detects a radiation dose rate of 0.1 μSv / h or higher, the system immediately triggers the following responses: First, it issues an audible and visual warning signal on-site to remind nearby personnel to evacuate; second, it automatically suspends the transport and transfer of isotope targets to prevent leakage and spread; third, it switches the corresponding neutron source channel from the operating state to the safe isolation state by cutting off the isolation valve and locking its transport mechanism, and can only be restored after manual confirmation and troubleshooting.

[0034] The online irradiation device and connecting pipes are equipped with a graded radiation protection structure along the axis. Specifically, a 10mm thick lead alloy shielding layer is installed at the outlet section of the channel near the reactor active area, where the radiation dose is highest. The high atomic number of lead effectively blocks gamma rays. On the reactor maintenance hall side, which is far from the reactor active area, a 5mm thick composite shielding layer of lead alloy and 30%~40% carbon fiber is installed. The radiation dose in this area has been significantly reduced, but personnel activity is frequent. In this area, lead alloy remains the main shielding material, while carbon fiber plays a role in reducing weight and enhancing structural rigidity.

[0035] The radiation level at the duct exit section is much higher than that on the maintenance hall side. Using thick shielding uniformly would result in unnecessary material waste and weight burden, while using thin shielding uniformly would fail to meet the protection requirements of the high-radiation area. Through this differentiated thickness and material design, lightweight structure and cost optimization can be achieved while meeting the radiation protection needs of different areas.

[0036] Each neutron source channel's integrated assembly is equipped with a built-in neutron flux monitoring probe and an energy spectrum monitoring probe. The neutron flux monitoring probe uses a miniature fission chamber or a self-powered detector to measure the absolute value of the neutron flux density within the channel in real time; the energy spectrum monitoring probe uses a multi-sphere spectrometer or a semiconductor detector to acquire neutron energy distribution information.

[0037] The data from the two sets of probes are connected to the control system, forming a closed-loop control circuit with the axial sliding mechanism: the control system compares the measured neutron flux and energy spectrum data with the target value in real time according to the preset component position formula corresponding to different isotope targets. If there is a deviation, the driving amount of the axial sliding mechanism is automatically adjusted until the measured value matches the target value.

[0038] An arrangement and online irradiation method for an online irradiation device based on a high-temperature gas-cooled reactor specifically includes the following steps: S1: Based on the geometric symmetry of the reactor, three neutron source channels with angles of 30°, 150°, and 270° are selected on the top cover of the pressure vessel, and connecting pipes and integrated components are installed in these channels.

[0039] S2: The online irradiation device is fixed in the reactor maintenance hall, and three sets of connecting pipes pass through the compartment cover and are sealed to the three neutron source channels one by one; then the target dynamic positioning system, graded radiation protection structure and distributed leakage early warning system are debugged to ensure that each subsystem functions normally and the interlocking is reliable.

[0040] S3: Integrated components are coaxially nested inside the active region of the lower straight conduit of each neutron source channel, and initial in-reactor calibration is performed. The calibration process is as follows: Under the rated power operation of the reactor, the moderation module and the reflection module are sequentially adjusted to multiple preset axial positions through the axial sliding mechanism. At the same time, the neutron flux monitoring probe and energy spectrum monitoring probe built into the integrated component are used to collect neutron flux density and energy spectrum distribution data corresponding to each position in real time. The control system records these data and compares them with theoretical calculation values ​​to select the optimal component position parameters that meet the three typical operating conditions of thermal neutron enrichment, resonant neutron adaptation, and fast neutron enhancement, and stores them in the control system as a reference formula. The thermal neutron enrichment mode is suitable for medical short-half-life isotopes such as molybdenum-99 and technetium-99m, which are mainly produced through thermal neutron capture reactions; the resonance neutron adaptation mode is suitable for isotopes such as iodine-123, which require specific resonance energy level neutron excitation for efficient conversion; and the fast neutron enhancement mode is suitable for industrial tracer isotopes such as cobalt-60 and iridium-192, which need to be produced through fast neutron inelastic scattering or threshold energy reactions.

[0041] With this calibration, the three channels can be switched to the required operating conditions with one click during subsequent operation, enabling the zoned collaborative production of multiple types of isotopes.

[0042] S4: The isotope target is loaded into the inlet of the online irradiation device and descends along the connecting pipe to the predetermined irradiation position in the reactor active area. During the descent, the infrared positioning sensor of the target dynamic positioning system tracks the target position in real time. When the target is detected to deviate from the neutron flux peak area by more than ±2mm, the control system automatically adjusts the fine-tuning action of the conveying mechanism to recalibrate the target to the optimal irradiation position.

[0043] During irradiation, the system continuously calls the embedded isotope type database to match the optimal irradiation time, temperature threshold, and pressure threshold corresponding to the current target. When the irradiation duration reaches the preset value in the database, the system automatically triggers the target removal command, drives the conveying mechanism to lift the target in reverse to the device entrance, and quickly transfers it to the cooling and storage area through the shielding door to avoid the activity decay of short half-life isotopes due to irradiation time exceeding the limit.

[0044] During actual production operation, the first neutron source channel can be adjusted to the thermal neutron energy spectrum enrichment mode for the production of molybdenum-99 or technetium-99m; the second neutron source channel can be adjusted to the resonance neutron energy spectrum mode for the production of iodine-123; and the third neutron source channel can be adjusted to the fast neutron flux enhancement mode for the production of cobalt-60 or iridium-192. This enables parallel, coordinated, and customized irradiation production of three different types of isotopes within the same reactor and the same operating cycle, significantly improving the utilization efficiency and economic benefits of the device.

[0045] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A high-temperature gas-cooled reactor online irradiation device, characterized in that: The system includes three neutron source channels, an online irradiation device body, and integrated components. The neutron source channels are respectively located at 30°, 150°, and 270° angles on the top cover of the high-temperature gas-cooled reactor pressure vessel. Each neutron source channel is equipped with a connecting pipe. The online irradiation device body is located in the reactor maintenance hall and is connected to the connecting pipe. The other end of the connecting pipe extends to the reactor active area. The integrated components are nested inside the connecting pipe in the irradiation section near the reactor active area. The integrated components include a moderation module, a reflection module, and an axial sliding mechanism. The integrated components in the three neutron source channels are independent of each other. The axial coverage height of the moderation module and the reflection module is adjusted by the axial sliding mechanism to independently control the neutron energy spectrum and neutron flux inside each neutron source channel.

2. The online irradiation device for a high-temperature gas-cooled reactor as described in claim 1, characterized in that: The connecting pipe includes an upper curved conduit and a lower straight conduit. The upper curved conduit is angled to match the pressure vessel top cover, and the lower straight conduit extends vertically to the reactor active area. The online irradiation device integrates a target dynamic positioning system, which includes an embedded isotope type database and infrared positioning sensors spaced apart along the axial direction of the lower straight conduit. The embedded isotope type database pre-stores the irradiation duration and temperature and pressure thresholds for molybdenum-99 and iodine-123. The infrared positioning sensors collect the isotope target position signals in real time and feed them back to the control system, achieving a positioning accuracy of ±2mm to ensure that the isotope target is in the neutron flux peak region.

3. The online irradiation device for a high-temperature gas-cooled reactor as described in claim 1, characterized in that: The online irradiation device also integrates a distributed leakage early warning system, which includes radioactive leakage monitoring sensors arranged at both ends and intermediate nodes of the connecting pipeline. When any radioactive leakage monitoring sensor detects a radiation dose rate ≥0.1μSv / h, it triggers a local early warning, suspends the transfer of isotope targets, and locks the corresponding neutron source channel.

4. The online irradiation device for a high-temperature gas-cooled reactor as described in claim 1, characterized in that: The online irradiation device and connecting pipes are equipped with a graded radiation protection structure along the axis. The graded radiation protection structure includes a lead alloy shielding layer installed at the outlet section of the channel near the reactor active area and a lead alloy and carbon fiber composite shielding layer installed on the side of the reactor maintenance hall away from the reactor active area.

5. The online irradiation device for a high-temperature gas-cooled reactor as described in claim 1, characterized in that: The moderation module adopts a composite layered structure of graphite and zirconium hydride; the reflection module adopts a composite structure of beryllium alloy and stainless steel reflection layer; the integrated component is also equipped with a neutron energy spectrum flux monitoring probe, which is used to collect neutron parameters of each neutron source channel in real time and feed them back to the axial sliding mechanism in a closed loop.

6. The online irradiation device for a high-temperature gas-cooled reactor as described in claim 2, characterized in that: The adaptive adjustment mechanism for the duct axis is located at the connection between the upper curved guide tube and the lower straight guide tube. The adaptive adjustment mechanism for the duct axis includes an electric actuator and a displacement sensor, which can compensate for an installation error of ±3°, so that the axial deviation between the upper curved guide tube and the lower straight guide tube after correction is ≤0.3mm.

7. The online irradiation device for a high-temperature gas-cooled reactor as described in claim 1, characterized in that: Each neutron source channel is equipped with a built-in neutron flux monitoring probe and an energy spectrum monitoring probe. The neutron flux monitoring probe and the energy spectrum monitoring probe are connected to the control system to form a closed-loop control, and the component position formula corresponding to different isotope targets is preset.

8. An arrangement and online irradiation method for a high-temperature gas-cooled reactor online irradiation device based on any one of claims 1-7, characterized in that, Includes the following steps: S1: Based on the reactor's geometric symmetry, three neutron source channels with angles of 30°, 150°, and 270° are selected on the pressure vessel top cover, and connecting pipes and integrated components are installed inside the neutron source channels; S2: Fix the online irradiation device in the reactor maintenance hall and connect it to three neutron source channels through connecting pipes to debug the target dynamic positioning system, graded radiation protection structure and distributed leakage early warning system; S3: Coaxially nested integrated components are installed inside the active region of the lower straight guide tube of each neutron source channel to perform initial in-pile calibration and solidify the energy spectrum reference for three working conditions: thermal neutron enrichment, resonant neutron adaptation, and fast neutron enhancement. S4: The isotope target is loaded into the inlet of the online irradiation device and sent down to the reactor active area for irradiation through the connecting pipe. The target is then positioned by the target dynamic positioning system and removed in the reverse direction after irradiation is completed.

9. The arrangement and online irradiation method as described in claim 8, characterized in that, In step S4: the embedded isotope type database is called to match the optimal irradiation time, temperature threshold and pressure threshold of the current isotope target; when the irradiation time of the isotope target reaches the preset time, the isotope target removal command is triggered, and the conveying mechanism is driven to lift the target to the device inlet in the reverse direction.

10. The arrangement and online irradiation method as described in claim 8, characterized in that, In step S3: the first neutron source channel is adjusted to the thermal neutron energy spectrum enrichment mode; the second neutron source channel is adjusted to the resonant neutron energy spectrum mode; and the third neutron source channel is adjusted to the fast neutron flux enhancement mode.

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