A gas-cooled small reactor system for online production of multiple radioisotopes

Abstract

The application relates to the technical field of nuclear energy technology, and discloses a gas-cooled small reactor system for on-line production of multiple radioisotopes. 235 The gas-cooled small reactor core has a reduced core diameter and height, increased core nuclear fuel enrichment and increased side reflector thickness; the gas-cooled small reactor core comprises a side reflector, core nuclear fuel and a core outlet part, the side reflector is provided with a control rod channel and a neutron irradiation channel; the gas-cooled small reactor further comprises a reactor pressure vessel, and the gas-cooled small reactor core is arranged in the reactor pressure vessel; the gas-cooled small reactor system further comprises a cooling assembly for providing cold helium for the gas-cooled small reactor; the helium temperature of the core outlet part in the system is designed to be 350-400 DEG C, and the pressure range of the cold helium in the cooling assembly is designed to be 2.5-4.5 MPa; the application has the advantages of improved production efficiency and capacity, prolonged service life of equipment and facilitated construction.

Description

Technical Field

[0001] This invention relates to a gas-cooled small reactor system for online production of multiple radioactive isotopes, belonging to the technical field of nuclear energy technology. Background Technology

[0002] Isotopes are nuclides with the same atomic number but different mass numbers. Radioactive isotopes are isotopes with unstable nuclei that spontaneously emit radiation (α, β, γ, etc.). The main production methods for radioactive isotopes include irradiating targets with reactor neutrons (referred to as "reactor irradiation"), bombarding targets with accelerators (referred to as "reactor irradiation"), and extraction from spent reactor fuel. Currently, reactor irradiation is the primary method for producing radioactive isotopes.

[0003] In existing technologies, one of the main uses of research reactors (mostly pool-type reactors, or "pool-type research reactors") both domestically and internationally is the research and production of radioactive isotopes. Pool-type research reactors often have many advantages in isotope production, such as high neutron flux rates, dedicated neutron irradiation channels, flexible operation, and supporting equipment for isotope extraction, purification, and encapsulation. Therefore, pool-type research reactors are currently the main type of reactor used for radioactive isotope production globally. However, these pool-type research reactors generally belong to first-generation nuclear energy technology.

[0004] The Generation IV International Forum has promoted Generation IV nuclear energy systems. Due to its inherent safety, high power generation efficiency, and economic advantages, the pebble bed high-temperature gas-cooled reactor (PTC) is considered one of the most promising technologies to meet the requirements of Generation IV nuclear energy systems. However, existing PEC technologies have the following drawbacks: 1. The level of average thermal neutron fluence directly affects the production efficiency of radioactive isotopes. Currently, the average thermal neutron fluence of pebble bed high-temperature gas-cooled reactor cores is generally no higher than 7. 10 13 n / (cm 2 The production capacity is on the order of s, which results in low production efficiency and insufficient capacity.

[0005] 2. The helium temperature at the core outlet of the pebble bed high-temperature gas-cooled reactor is between 500 and 800°C. This temperature can easily cause the structural materials of equipment such as reactor metal components, hot gas ducts, steam generator heat transfer tubes, and intermediate heat exchanger heat transfer components to fracture due to high-temperature creep-fatigue deformation, resulting in a short service life of the equipment.

[0006] 3. In order to match the optimal pressure ratio of the thermodynamic cycle and thus obtain the highest power generation efficiency, the helium pressure of the pebble bed high-temperature gas-cooled reactor cooling device is about 7MPa. Such high-pressure cooling devices are not only difficult to transport, but also pose significant challenges to construction on site, making them difficult to build. Summary of the Invention

[0007] To address the aforementioned problems in the existing technology, this invention provides a gas-cooled small reactor system for online production of multiple radioactive isotopes.

[0008] The technical solution of the present invention is as follows: In a first aspect, the present invention provides a design method for a gas-cooled small reactor core, comprising the following steps: Compared to the traditional pebble bed high-temperature gas-cooled reactor core, which has a core diameter of about 3m and a height of about 11m, the core diameter and height of the gas-cooled miniature reactor core are reduced. Specifically, the core diameter of the gas-cooled miniature reactor core is designed to be 1.8 to 2m, and the core height is designed to be 6.0 to 6.5m.

[0009] Compared to traditional reactor core nuclear fuel 235 A pebble bed high-temperature gas-cooled reactor core with a U enrichment of approximately 8.5% improves the core nuclear fuel of the gas-cooled small modular reactor core. 235 U enrichment, specifically: the core nuclear fuel of the gas-cooled small modular reactor core. 235 The U enrichment level is designed to be 16–19.5% (the requirement of the International Atomic Energy Agency for nuclear fuel in civilian nuclear facilities). 235 The U enrichment level does not exceed 20%, therefore the design meets the requirements.

[0010] Compared to the traditional pebble bed high-temperature gas-cooled reactor core with a side reflector thickness of 750mm, the side reflector thickness of the gas-cooled miniature reactor core is increased, specifically by designing the side reflector thickness of the gas-cooled miniature reactor core to be 1000mm.

[0011] The gas-cooled small reactor core obtained using the above design method can achieve an average thermal neutron fluence of 1.2 × 10⁻⁶ in its side reflector. 14 n / (cm 2 The high flux levels of s) and above exceed the average thermal neutron flux levels of typical pool-type research reactors and conventional pebble bed high-temperature gas-cooled reactor cores.

[0012] Secondly, the present invention provides a gas-cooled small reactor system for online production of multiple radioactive isotopes, comprising several gas-cooled small reactors. Each gas-cooled small reactor includes a gas-cooled small reactor core designed using the aforementioned design method. The gas-cooled small reactor core includes a cylindrical side reflector, core nuclear fuel disposed inside the side reflector, and a core outlet located at the bottom of the side reflector. The side reflector has several vertically arranged control rod channels and neutron irradiation channels. Each control rod channel is equipped with a control rod, and each neutron irradiation channel is equipped with a neutron irradiation target. The gas-cooled small reactor also includes a reactor pressure vessel disposed below the reactor hall floor, and the gas-cooled small reactor core is disposed within the reactor pressure vessel. The gas-cooled small reactor system also includes a cooling assembly, which is connected to each gas-cooled small reactor to provide cooling helium gas for each gas-cooled small reactor.

[0013] Furthermore, the cooling assembly includes a helium coolant circulating fan for discharging cooling helium and a heat exchanger connected in communication with the helium coolant circulating fan. One end of a cold helium pipe is connected to the outlet of the helium coolant circulating fan, and the other end of the cold helium pipe is connected in communication with the interior of the side reflector layer of each gas-cooled miniature reactor core. One end of a hot helium pipe is connected to the inlet of the heat exchanger, and the other end of the hot helium pipe is connected in communication with the outlet of each reactor core.

[0014] Furthermore, the helium temperature at the core outlet is designed to be 350–400°C, and the helium pressure in the helium coolant circulating fan is in the range of 2.5–4.5 MPa.

[0015] Furthermore, the side reflector layer is also provided with a first channel and a second channel that correspond one-to-one with the neutron irradiation channel. The neutron irradiation channel and the corresponding first and second channels are connected. The first and second channels are distributed vertically, with the first channel located above the second channel. The neutron irradiation target is located in the neutron irradiation channel between the first and second channels. Cooling helium gas entering the side reflector layer through the cold helium pipe enters the neutron irradiation channel through the first channel, and the cooling helium gas entering the neutron irradiation channel exits the neutron irradiation channel through the second channel.

[0016] Furthermore, a target loading and unloading device for loading and unloading neutron irradiation targets is also provided on the floor of the reactor hall. The top of each neutron irradiation channel extends to the floor of the reactor hall, and a helium isolation valve is installed on each neutron irradiation channel.

[0017] Furthermore, an insulation layer is also provided inside the reactor pressure vessel, which is located between the inner wall of the reactor pressure vessel and the gas-cooled small reactor core.

[0018] The present invention has the following beneficial effects: 1. This invention provides a design method for a gas-cooled small reactor core. The average thermal neutron flux of the side reflector layer of the gas-cooled small reactor core obtained by this design method can exceed the average thermal neutron flux level of the core of a typical pool-type research reactor and a conventional pebble bed high-temperature gas-cooled reactor. This can improve the production efficiency and capacity of the gas-cooled small reactor system using this gas-cooled small reactor core, and has the advantage of improving production efficiency and capacity.

[0019] 2. This invention designs the helium temperature at the core outlet to be 350–400°C. This avoids the high-temperature creep-fatigue deformation and fracture of equipment structural materials such as reactor metal components, hot gas ducts, steam generator heat transfer tubes, and intermediate heat exchanger heat transfer components when the operating temperature is ≥425°C, thus extending the service life of the equipment. Simultaneously, it reduces the temperature of the neutron irradiation channels in the side reflector, allowing for the production of targets with higher heat generation rates in the side reflector. 131 I, 3 The conditions were created for radioactive isotopes such as H.

[0020] 3. This invention reduces the helium pressure range of the coolant in the helium coolant circulating fan to 2.5–4.5 MPa. This lower coolant helium pressure not only solves the transportation problem of the high-pressure vessel, but also provides technical flexibility for subsequent construction, such as implementing pneumatic nuclear fuel circulation and pneumatic loading and unloading of nuclear fuel elements, and on-site pouring of steel-faced concrete or prestressed concrete reactor pressure vessels for gas-cooled small modular reactor systems. It also facilitates the construction of the gas-cooled small modular reactor system provided by this invention in inland areas. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 for Figure 1 Sectional view of AA.

[0022] The reference numerals in the figure are as follows: 1. Gas-cooled small modular reactor core; 2. Core nuclear fuel; 3. Side reflector; 4. Core outlet; 5. Control rod channel; 6. Neutron irradiation channel; 7. Control rod; 8. Neutron irradiation target; 9. Reactor hall floor; 10. Reactor pressure vessel; 11. Cooling assembly; 12. Helium coolant circulation fan; 13. Heat exchanger; 14. Cold helium pipeline; 15. Hot helium pipeline; 16. First channel; 17. Second channel; 18. Target loading and unloading device; 19. Helium isolation valve; 20. Insulation layer. Detailed Implementation

[0023] Before introducing the embodiments, the following explanations are provided for any technical terms or industry jargon that may appear, in order to facilitate understanding.

[0024] The term "traditional pebble bed high-temperature gas-cooled reactor core" specifically refers to the "HTR-MODUL" design concept proposed by the Jülich Research Centre in Germany in the 1970s and 80s. This concept was developed in response to the industry's then-current pursuit of higher nuclear safety standards, aiming to design a safe reactor that requires no active intervention in the event of any accident. Traditional pebble bed high-temperature gas-cooled reactor cores adhere to specific safety standards, design standards, performance and operational standards, and economic and engineering standards within the industry.

[0025] Gas-cooled small modular reactors (SMRs) refer to helium-cooled reactors with smaller core size, lower thermal power, and lower core master parameters compared to small-capacity (100-400 MWt) pebble bed high-temperature gas-cooled reactors. They also employ a non-stop refueling method. In the online production of multiple radioisotopes gas-cooled small modular reactor system described in this invention, the gas-cooled small reactor adopts the inherent safety design of fourth-generation nuclear energy systems similar to existing pebble bed high-temperature gas-cooled reactors, fundamentally eliminating the possibility of reactor core meltdown. This creates conditions for inland construction and local supply of radioisotopes.

[0026] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0027] Example: Please refer to Figure 1 and Figure 2 This embodiment provides a gas-cooled small modular reactor (SMR) system for online production of multiple radioactive isotopes, comprising several SMRs. Each SMR includes a SMR core 1, which includes a cylindrical side reflector 3, core nuclear fuel 2 disposed within the side reflector 3, and a core outlet 4 located at the bottom of the side reflector 3. The SMR core 1 is designed using the following method: Compared to the traditional pebble bed high-temperature gas-cooled reactor core with a core diameter of 1.8 m and a height of 2 m, the core diameter and height of the gas-cooled small reactor core 1 are reduced. Specifically, the core diameter of the gas-cooled small reactor core 1 is designed to be 1.8 to 2 m, and the core height of the gas-cooled small reactor core 1 is designed to be 6.0 to 6.5 m.

[0028] Compared to traditional reactor core nuclear fuel 2 235 A pebble bed high-temperature gas-cooled reactor core with a U enrichment of approximately 8.5% will improve the core nuclear fuel 2 of gas-cooled small reactor core 1. 235 U enrichment, specifically: the core nuclear fuel 2 of gas-cooled small reactor core 1. 235 The U enrichment level was designed to be 16–19.5%.

[0029] Compared to the traditional pebble bed high-temperature gas-cooled reactor core with a side reflector layer 3 thickness of 750 mm, the thickness of the side reflector layer 3 in the gas-cooled miniature reactor core 1 is increased, specifically by designing the side reflector layer 3 thickness to be 1000 mm. In this embodiment, the side reflector layer 3 is made of graphite material, and the average flux rate of the thermal neutron neutron energy <0.625 MeV within the graphite side reflector layer 3 can reach over 90% of the core.

[0030] The aforementioned design method enables the average thermal neutron fluence of core 1 of the gas-cooled miniature reactor to reach 1.2 × 10⁻⁶. 14 The high flux levels of n / (cm2s) and above exceed the average thermal neutron flux levels of typical pool-type research reactors and conventional pebble bed high-temperature gas-cooled reactor cores, creating conditions for the efficient production of radioisotopes.

[0031] The side reflector layer 3 has several vertically arranged control rod channels 5 and neutron irradiation channels 6. The specific distribution and number of control rod channels 5 and neutron irradiation channels 6 can be selected according to actual conditions and are not limited here. In this embodiment, in order not to affect the radial symmetry of the gas-cooled small reactor core 1, the control rod channels 5 and neutron irradiation channels 6 are arranged in a circular array on the side reflector layer 3 with the axis of the gas-cooled small reactor core 1 as the array center. The neutron irradiation channels 6 are staggered with the control rod channels 5, and the neutron irradiation channels 6 are set closer to the center of the gas-cooled small reactor core 1 than the control rod channels 5, thereby obtaining a higher neutron flux. Each control rod channel 5 is equipped with a control rod 7, and each neutron irradiation channel 6 is equipped with a neutron irradiation target 8. In this embodiment, the number of neutron irradiation channels 6 can be even, preferably 16 or 24. By loading different neutron irradiation targets 8 into groups of four neutron irradiation channels 6 distributed at 90° intervals within the side reflector layer 3, the simultaneous production of four or six radioactive isotopes can be achieved. This creates conditions for flexibly arranging the production of various radioactive isotopes and producing short-half-life medical radioactive isotopes. In actual use, graphite liner tubes can also be installed inside the neutron irradiation channels 6 to protect the inner wall of the neutron irradiation channels 6.

[0032] The aforementioned gas-cooled small reactor also includes a reactor pressure vessel 10 located below the reactor hall floor 9. The gas-cooled small reactor core 1 is located inside the reactor pressure vessel 10. An insulation layer 20 is also provided inside the reactor pressure vessel 10. The insulation layer 20 is located between the inner wall of the reactor pressure vessel 10 and the gas-cooled small reactor core 1, so as to avoid heat exchange between the gas-cooled small reactor core 1 and the reactor pressure vessel 10, thereby reducing heat loss during subsequent production.

[0033] This gas-cooled small reactor system also includes a cooling assembly 11, which is connected to each gas-cooled small reactor to provide cooling helium to each gas-cooled small reactor.

[0034] In this embodiment, the cooling assembly 11 includes a helium coolant circulating fan 12 for discharging cooling helium and a heat exchanger 13 connected in communication with the helium coolant circulating fan 12. The helium coolant circulating fan 12 is equipped with a corresponding helium coolant storage tank to discharge cooling helium when it starts working. One end of a cold helium pipe 14 is connected to the outlet of the helium coolant circulating fan 12. The other end of the cold helium pipe 14 is connected to the interior of the side reflector layer 3 of each gas-cooled small reactor core 1. The end of the cold helium pipe 14 that is connected to the interior of the side reflector layer 3 is positioned close to the top of the side reflector layer 3. When the helium coolant circulating fan 12 starts working, the cooling helium it discharges can enter the gas-cooled small reactor core 1 through the cold helium pipe 14. One end of a hot helium pipe 15 is connected to the inlet of the heat exchanger 13. The other end of the hot helium pipe 15 is connected to the outlet 4 of each core. After the gas-cooled small reactor core 1 is cooled, the helium gas can flow back to the cooling assembly 11 through the hot helium pipe 15, and the heat exchanger 13 recovers the heat in the helium gas at this time.

[0035] To ensure that the cooling helium gas can cool the neutron irradiation target 8, in this embodiment, the side reflector layer 3 is further provided with a first channel 16 and a second channel 17 that correspond one-to-one with the neutron irradiation channel 6. The neutron irradiation channel 6 and the corresponding first channel 16 and second channel 17 are connected. The first channel 16 and the second channel 17 are distributed vertically, with the first channel 16 located above the second channel 17. The first channel 16 is also located below the end of the cold helium pipe 14 that connects to the interior of the side reflector layer 3 to ensure the inflow of cooling helium gas. The neutron irradiation target 8 is disposed in the neutron irradiation channel 6 between the first channel 16 and the second channel 17. Cooling helium gas entering the side reflector layer 3 from the cold helium pipe 14 can enter the neutron irradiation channel 6 through the first channel 16 to cool the neutron irradiation target 8. After the cooling helium gas entering the neutron irradiation channel 6 has cooled the neutron irradiation target 8, it can be discharged from the neutron irradiation channel 6 through the second channel 17 and re-enter the side reflector layer 3. Finally, it flows from the core outlet 4 into the hot helium pipe 15 for recovery.

[0036] In this embodiment, the helium temperature at the core outlet 4 is designed to be 350–400°C. This design can be achieved by controlling the temperature and rate of the introduced cooling helium. By setting the helium temperature at the core outlet 4 to 350–400°C, the fracture of equipment structural materials such as reactor metal components, hot gas ducts, steam generator heat transfer tubes, and intermediate heat exchanger heat transfer components due to high-temperature creep-fatigue deformation is avoided when the operating temperature is ≥425°C, thus extending the equipment's service life. Simultaneously, it also reduces the temperature of the neutron irradiation channel 6 in the side reflector layer 3, allowing for the production of targets with higher heat generation rates in the side reflector layer 3. 131 I, 3 The conditions were created for radioactive isotopes such as H.

[0037] In this embodiment, the helium pressure range of the coolant in the helium coolant circulating fan 12 is 2.5–4.5 MPa. By reducing the helium pressure range of the coolant in the helium coolant circulating fan 12 to 2.5–4.5 MPa, this lower coolant helium pressure not only solves the transportation problem of the high-pressure vessel, but also provides technical flexibility for subsequent construction, such as implementing pneumatic nuclear fuel circulation and pneumatic loading and unloading of nuclear fuel elements, and on-site pouring of steel-faced concrete or prestressed concrete reactor pressure vessel 10 for the gas-cooled small reactor system. This facilitates the construction of the gas-cooled small reactor system provided by this invention in inland areas.

[0038] In this embodiment, a target loading and unloading device 18 for loading and unloading neutron irradiation target 8 is also provided on the reactor hall floor 9. The top of each neutron irradiation channel 6 extends to the reactor hall floor 9, and a helium isolation valve 19 is installed on each neutron irradiation channel 6. The helium isolation valve 19 is provided to prevent helium from escaping from the neutron irradiation channel 6.

[0039] In this embodiment, during production operations, the neutron irradiation target 8 is loaded into the neutron irradiation channel 6 through the target loading and unloading device 18. Then, the neutron irradiation rate is controlled in a corresponding manner by using the control rod 7, and the required cooling helium is provided by the control cooling component 11, so that the required isotope production operations can be carried out.

[0040] In practical use, the gas-cooled small modular reactor (SMR) system provided in this embodiment can adopt a modular design. A single SMR system can consist of 2 to 4 SMRs, along with supporting cooling components, nuclear fuel element loading and unloading systems, target loading and unloading devices, and other major equipment. The thermal power of a single SMR can range from 20 to 60 MWt. The modular design not only ensures that shutdown and maintenance of a single reactor does not affect the continuous supply of radioactive isotopes, but also reduces costs due to the smaller capacity of the modular SMRs. Furthermore, it allows for flexible selection of the construction scale of the modular reactors based on the scale of radioactive isotope production.

[0041] In practical applications, the types of radioactive isotopes suitable for production using the gas-cooled small reactor system provided in this embodiment include: 3 H, 14 C 32 P, 36 Cl、 51 Cr 89 Sr、 99 Mo、 125 I, 131 I, 131 Ba、 147 Nd, 153 Gd, 161 Tb, 169 Er、 177 Lu、 182 Ta、 188 W, 192 Ir、 203 Hg, 210 Po、 225 AC, 238 Pu、 241 Am、 47 Sc, etc.

[0042] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A design method for a gas-cooled small reactor core, characterized in that: Includes the following steps: Compared to traditional pebble bed high-temperature gas-cooled reactor cores, the core diameter and height of the gas-cooled small reactor core (1) are reduced; Compared to traditional pebble bed high-temperature gas-cooled reactor cores, the core nuclear fuel (2) of gas-cooled small reactor cores (1) is improved. 235 U enrichment; Compared to the traditional pebble bed high-temperature gas-cooled reactor core, the thickness of the side reflector layer (3) of the gas-cooled small reactor core (1) is increased.

2. The design method for a gas-cooled small reactor core according to claim 1, characterized in that: The core diameter of the gas-cooled small reactor (1) is 1.8 to 2 m, and the core height is 6.0 to 6.5 m.

3. The design method for a gas-cooled small reactor core according to claim 1, characterized in that: The core nuclear fuel (2) of the gas-cooled small reactor core (1). 235 The enrichment level of U was 16–19.5%.

4. The design method for a gas-cooled small reactor core according to claim 1, characterized in that: The thickness of the side reflector layer (3) of the gas-cooled small reactor core (1) is 1000 mm.

5. A gas-cooled small reactor system for online production of multiple radioactive isotopes, characterized in that: The system includes several gas-cooled small reactors, each including a gas-cooled small reactor core (1) designed using any of the design methods described in claims 1 to 4. The gas-cooled small reactor core (1) includes a side reflector (3) arranged in a cylindrical structure, core nuclear fuel (2) disposed inside the side reflector (3), and a core outlet (4) disposed at the bottom of the side reflector (3). The side reflector (3) has several vertically arranged control rod channels (5) and neutron irradiation channels (6). Each control rod channel (5) is equipped with a control rod (7), and each neutron irradiation channel (6) is equipped with a neutron irradiation target (8). The gas-cooled small reactor also includes a reactor pressure vessel (10) located below the reactor hall floor (9), and the gas-cooled small reactor core (1) is located inside the reactor pressure vessel (10); The gas-cooled small stack system also includes a cooling component (11), which is connected to each gas-cooled small stack to provide cooling helium to each gas-cooled small stack.

6. A gas-cooled small reactor system for online production of multiple radioactive isotopes according to claim 5, characterized in that: The cooling assembly (11) includes a helium coolant circulating fan (12) for discharging cooling helium and a heat exchanger (13) connected in communication with the helium coolant circulating fan (12). One end of a cold helium pipe (14) is connected to the outlet of the helium coolant circulating fan (12), and the other end of the cold helium pipe (14) is connected in communication with the interior of the side reflector layer (3) of each gas-cooled small reactor core (1). One end of a hot helium pipe (15) is connected to the inlet of the heat exchanger (13), and the other end of the hot helium pipe (15) is connected in communication with the outlet (4) of each reactor core.

7. A gas-cooled small reactor system for online production of multiple radioactive isotopes according to claim 6, characterized in that: The helium temperature of the core outlet (4) is designed to be 350-400°C, and the helium pressure of the coolant in the helium coolant circulating fan (12) is 2.5-4.5 MPa.

8. A gas-cooled small reactor system for online production of multiple radioactive isotopes according to claim 6, characterized in that: The side reflector layer (3) is also provided with a first channel (16) and a second channel (17) that correspond one-to-one with the neutron irradiation channel (6). The neutron irradiation channel (6) and the corresponding first channel (16) and second channel (17) are connected. The first channel (16) and the second channel (17) are distributed vertically. The first channel (16) is located above the second channel (17). The neutron irradiation target (8) is located in the neutron irradiation channel (6) between the first channel (16) and the second channel (17). Cooling helium gas entering the side reflector layer (3) from the cold helium pipe (14) enters the neutron irradiation channel (6) through the first channel (16). Cooling helium gas entering the neutron irradiation channel (6) exits the neutron irradiation channel (6) through the second channel (17).

9. A gas-cooled small reactor system for online production of multiple radioactive isotopes according to claim 5, characterized in that: The reactor hall floor (9) is also equipped with a target loading and unloading device (18) for loading and unloading neutron irradiation target (8). The top of each neutron irradiation channel (6) extends to the reactor hall floor (9), and each neutron irradiation channel (6) is equipped with a helium isolation valve (19).

10. A gas-cooled small reactor system for online production of multiple radioactive isotopes according to claim 5, characterized in that: The reactor pressure vessel (10) is also provided with an insulation layer (20), which is located between the inner wall of the reactor pressure vessel (10) and the gas-cooled small reactor core (1).

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