Neutron irradiation method and system for side reflecting layer of pebble-bed high-temperature gas cooled reactor

Abstract

The invention provides a neutron irradiation method and system for a side reflecting layer of a pebble-bed high-temperature gas cooled reactor. The method comprises the following steps: acquiring a first irradiation pore channel of the side reflecting layer; in response to the situation that the first thermal neutron fluence rate of the first irradiation pore channel is located in a preset interval, obtaining a second irradiation pore channel after the neutron screen assembly is arranged; in response to the fact that the second thermal neutron fluence rate of the second irradiation pore channel meets quasi-uniform distribution, safety parameters of the to-be-irradiated sample subjected to neutron irradiation by the pebble-bed high-temperature gas cooled reactor in the second irradiation pore channel of the side reflecting layer are obtained, and in response to the fact that the safety parameters meet safety conditions, the second irradiation pore channel serves as a target irradiation pore channel; neutron irradiation is performed on a to-be-irradiated sample based on the target irradiation pore channel, the irradiation pore channel is arranged in the side reflecting layer of the pebble-bed high-temperature gas cooled reactor, and uniform distribution of thermal neutron fluence rate in the irradiation pore channel is realized by arranging the neutron screen assembly, so that the problem that uniform irradiation is difficult to realize by a conventional irradiation pore channel is solved; and uniform irradiation of the to-be-irradiated sample is realized.

Description

Technical Field

[0001] The present application relates to the technical field of the application of pebble bed high-temperature gas-cooled reactors, and particularly relates to a method and system for neutron irradiation of the side reflector of a pebble bed high-temperature gas-cooled reactor. Background Art

[0002] Currently, pebble bed high-temperature gas-cooled reactors generally use spherical fuel elements (referred to as fuel pebbles). As Figure 1 shown, the hemisphere after cutting a fuel pebble includes a non-fuel area 11 on the outside and a fuel area 12 on the inside. The fuel area 12 encapsulates a plurality of fuel particles, and the fuel particles sequentially include an outer dense pyrolytic carbon P y C layer 13, a silicon carbide SiC layer 14, an inner dense pyrolytic carbon P y C layer 15, a loose pyrolytic carbon P y C layer 16, and a uranium dioxide UO2 core 17. The core structure of a pebble bed high-temperature gas-cooled reactor can be simply described as a cylindrical pebble bed randomly filled with spherical fuel elements in the middle of the core. As Figure 2 shown, outside the pebble bed are a graphite in-core structure, a carbon in-core structure, a metal in-core structure, and a reactor pressure vessel in sequence. Among them, the graphite in-core structure includes a top reflector 21, a side reflector 22, and a bottom reflector 23. As Figure 3 shown, control rod channels 31, absorber ball channels 32, and cold helium gas channels 33 are generally arranged in the side reflector 22 of the graphite in-core structure.

[0003] Since the neutron fluence rate in most reactor irradiation channels is non-uniform, for isotopes or materials with relatively high requirements for neutron fluence rate uniformity, the existing irradiation channels cannot meet the irradiation requirements. Summary of the Invention

[0004] The purpose of the present application is to solve at least one of the technical problems in the above-mentioned technologies to a certain extent.

[0005] The first aspect of the present application provides a method for neutron irradiation of the side reflector of a pebble bed high-temperature gas-cooled reactor, including: obtaining a first irradiation channel of the side reflector and obtaining the first thermal neutron fluence rate of the first irradiation channel; in response to the first thermal neutron fluence rate being within a preset interval, obtaining a second irradiation channel after arranging a neutron screen assembly and obtaining the second thermal neutron fluence rate of the second irradiation channel; in response to the second thermal neutron fluence rate satisfying a quasi-uniform distribution, obtaining the safety parameters of the pebble bed high-temperature gas-cooled reactor for neutron irradiation of a sample to be irradiated in the second irradiation channel of the side reflector, and in response to the safety parameters satisfying the safety conditions, using the second irradiation channel as the target irradiation channel of the side reflector; based on the target irradiation channel, performing neutron irradiation on the sample to be irradiated.

[0006] The second aspect of the present application provides a neutron irradiation system for the side reflector of a pebble bed high-temperature gas-cooled reactor, including: a first acquisition module, configured to acquire the first irradiation channel of the side reflector and acquire the first thermal neutron fluence rate of the first irradiation channel; a second acquisition module, configured to, in response to the first thermal neutron fluence rate being within a preset range, acquire the second irradiation channel after arranging the neutron shield assembly and acquire the second thermal neutron fluence rate of the second irradiation channel; a third acquisition module, configured to, in response to the second thermal neutron fluence rate satisfying a quasi-uniform distribution, acquire the safety parameters for neutron irradiation of the sample to be irradiated in the second irradiation channel of the side reflector of the pebble bed high-temperature gas-cooled reactor, and a determination module, configured to, in response to the safety parameters satisfying the safety conditions, use the second irradiation channel as the target irradiation channel of the side reflector; an irradiation module, configured to perform neutron irradiation on the sample to be irradiated based on the target irradiation channel.

[0007] In the third aspect of the embodiments of the present application, a non-transitory computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, it implements the neutron irradiation method for the side reflector of the pebble bed high-temperature gas-cooled reactor provided in the first aspect above.

[0008] The neutron irradiation method for the side reflector of the pebble bed high-temperature gas-cooled reactor provided in the present application includes: acquiring the first irradiation channel of the side reflector and acquiring the first thermal neutron fluence rate of the first irradiation channel; in response to the first thermal neutron fluence rate being within a preset range, acquiring the second irradiation channel after arranging the neutron shield assembly and acquiring the second thermal neutron fluence rate of the second irradiation channel; in response to the second thermal neutron fluence rate satisfying a quasi-uniform distribution, acquiring the safety parameters for neutron irradiation of the sample to be irradiated in the second irradiation channel of the side reflector of the pebble bed high-temperature gas-cooled reactor; in response to the safety parameters satisfying the safety conditions, using the second irradiation channel as the target irradiation channel of the side reflector; and performing neutron irradiation on the sample to be irradiated based on the target irradiation channel. Thus, by arranging an irradiation channel in the side reflector of the pebble bed high-temperature gas-cooled reactor and arranging a neutron shield assembly, the present application realizes a uniform distribution of the thermal neutron fluence rate in the irradiation channel, solves the problem that it is difficult to achieve uniform irradiation in a conventional irradiation channel, and realizes uniform irradiation of the sample to be irradiated by rotating or transposing the sample to be irradiated, etc., which is feasible, expands the application field of the pebble bed high-temperature gas-cooled reactor, and is conducive to improving the economy and efficiency.

[0009] Additional aspects and advantages of the present application will be given in part in the following description, will become apparent in part from the following description, or will be understood through the practice of the present application. Description of the Drawings

[0010] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of the embodiments in conjunction with the drawings, where:

[0011] Figure 1 Schematic diagram of the structure of a fuel element of a pebble bed high-temperature gas-cooled reactor provided by an embodiment of the present application;

[0012] Figure 2 Schematic diagram of the core structure of a pebble bed high-temperature gas-cooled reactor provided by an embodiment of the present application;

[0013] Figure 3 Schematic diagram of the structure of the side reflector channel of a pebble bed high-temperature gas-cooled reactor provided by an embodiment of the present application;

[0014] Figure 4 Schematic flow chart of a method for neutron irradiation of the side reflector of a pebble bed high-temperature gas-cooled reactor provided by an embodiment of the present application;

[0015] Figure 5 Distribution diagram of thermal neutron fluence rate of the core and side reflector of a pebble bed high-temperature gas-cooled reactor provided by an embodiment of the present application;

[0016] Figure 6 Schematic diagram of an arrangement of irradiation channels provided by an embodiment of the present application;

[0017] Figure 7 Distribution diagram of comparison of thermal neutron fluence rate before and after arranging a neutron shield assembly provided by an embodiment of the present application;

[0018] Figure 8 Schematic diagram of the structure of a neutron irradiation system for the side reflector of a pebble bed high-temperature gas-cooled reactor provided by an embodiment of the present application. Detailed implementation manners

[0019] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and should not be construed as limiting the present application.

[0020] It should be noted that the pebble bed high-temperature gas-cooled reactor uses graphite in-core components as the side reflector to slow down the neutrons escaping from the core and partially reflect them back into the core, which can improve the neutron utilization rate and reduce the number of fuel elements loaded in the core. Since the side reflector has a moderating effect on neutrons, some fast neutrons entering the side reflector can be slowed down to thermal neutrons. Therefore, the thermal neutron fluence rate in the side reflector will increase to a certain extent compared with the core edge. According to the reactor physics calculation of the pebble bed high-temperature gas-cooled reactor, the thermal neutron fluence rate in the side reflector is considerable and is equivalent to that in the reactor core. For example, the thermal neutron fluence rate in the core is 7×10 13 n / cm 2 ·s, and the thermal neutron fluence rate in the side reflector is 5×10 13n / cm 2 ·s. Therefore, by arranging irradiation channels in the side reflector of the pebble bed high-temperature gas-cooled reactor, it can be fully utilized for isotope or material irradiation production, expanding the application field of the pebble bed high-temperature gas-cooled reactor and being beneficial to improving economic and social benefits.

[0021] The pebble bed high-temperature gas-cooled reactor is a columnar core reactor. Similar to other types of reactors such as pressurized water reactors, the neutron fluence rate in the axial direction of the columnar reactor usually shows a cosine or approximately cosine distribution, with the highest at the center and gradually decreasing towards both ends. The specific distribution will vary due to the combined effects of control rod position, core arrangement, coolant flow, etc., but basically shows a cosine-like distribution. The distribution of the core neutron fluence rate in the axial direction results in the same distribution of the neutron fluence rate in the side reflector of the pebble bed high-temperature gas-cooled reactor, that is, the thermal neutron fluence rate in the irradiation channels of the side reflector is also unevenly distributed, with the highest in the middle and the lowest at both ends.

[0022] For the irradiation of some special isotopes or materials, such as neutron transmutation doping of single crystal silicon, a uniform neutron fluence rate in the irradiation channel is required during irradiation to meet the requirements of quasi-uniform irradiation and produce products that meet the quality requirements. Since the neutron fluence rate in the irradiation channels of most reactors is non-uniform, the realization of such requirements is restricted. Therefore, it is very necessary to develop an irradiation channel in the side reflector of the pebble bed high-temperature gas-cooled reactor for carrying out the irradiation of isotopes or materials with higher requirements for neutron fluence rate uniformity.

[0023] The following describes a neutron irradiation method and system for the side reflector of a pebble bed high-temperature gas-cooled reactor according to an embodiment of the present application with reference to the accompanying drawings.

[0024] Figure 4 It is a schematic flow chart of a neutron irradiation method for the side reflector of a pebble bed high-temperature gas-cooled reactor according to an embodiment of the present application. As Figure 4 shown, the method includes:

[0025] S401, obtain the first irradiation channel of the side reflector and obtain the first thermal neutron fluence rate of the first irradiation channel.

[0026] In the embodiment of the present application, the irradiation channel layout parameters of the side reflector can be obtained, and according to the irradiation channel layout parameters, the irradiation channels are arranged in the side reflector to obtain the first irradiation channel of the side reflector.

[0027] It should be noted that the irradiation channel layout parameters include but are not limited to: irradiation channel layout position, irradiation channel layout method, and irradiation channel diameter.

[0028] For example, since the side reflector will slow down the neutrons from the core, as Figure 5As shown in the figure, the abscissa is the core radius and the ordinate is the thermal neutron fluence rate. There will be a "peak" in the thermal neutron fluence rate inside the side reflector. The radial position of the irradiation channel can be set near the position with the highest thermal neutron fluence rate in the side reflector, that is, the irradiation channel is designed near the "peak", so that a larger thermal neutron fluence rate can be obtained in the irradiation channel, improving the efficiency of isotope or material irradiation. The irradiation channels can be arranged evenly in the circumferential direction, such as Figure 6 As shown, 3 irradiation channels (the first irradiation channel) are evenly distributed at intervals of 120° on the circumference, ensuring that each irradiation channel has the same interval angle in the circumferential direction to reduce the influence of target or material irradiation on the circumferential power, temperature, neutron fluence rate, etc. distribution of the reactor core. According to the actual situation of the pebble bed high-temperature gas-cooled reactor, a preset irradiation channel diameter interval can be obtained to ensure that the irradiation channel diameter is within the preset irradiation channel diameter interval to ensure that the strength of the inner components of the side reflector graphite pile meets the requirements.

[0029] In the embodiment of the present application, after obtaining the first irradiation channel of the side reflector, the first thermal neutron fluence rate of the first irradiation channel can be obtained.

[0030] In the embodiment of the present application, according to the characteristic data of the pebble bed high-temperature gas-cooled reactor, a physical calculation model of the pebble bed high-temperature gas-cooled reactor can be constructed, and the target calculation program can be called. Based on the physical calculation model of the pebble bed high-temperature gas-cooled reactor, the first thermal neutron fluence rate of the first irradiation channel can be obtained, where the target calculation program at least includes the VSOP program and / or the MCNP program.

[0031] Optionally, according to the core structure and size, fuel enrichment, fuel loading scheme, coolant flow rate and other characteristic data of the pebble bed high-temperature gas-cooled reactor, a physical calculation model of the pebble bed high-temperature gas-cooled reactor is constructed, and the special pebble bed high-temperature gas-cooled reactor design program VSOP program or the Monte Carlo calculation MCNP program is called to perform calculations based on the physical calculation model of the pebble bed high-temperature gas-cooled reactor to obtain the first thermal neutron fluence rate of the first irradiation channel.

[0032] Optionally, the VSOP program has advantages in reactor physical design and burnup calculation, while the MCNP program has advantages in accurately simulating the neutron transport process. The first thermal neutron fluence rate of the first irradiation channel can be obtained more accurately by coupling the VSOP program and the MCNP program.

[0033] S402, in response to the first thermal neutron fluence rate being within the preset interval, obtain the second irradiation channel after arranging the neutron shield assembly, and obtain the second thermal neutron fluence rate of the second irradiation channel.

[0034] In an embodiment of the present application, after obtaining the first thermal neutron fluence rate, it is possible to determine whether the first thermal neutron fluence rate is within a preset interval, and based on the determination result, determine whether to adjust the irradiation channel layout parameters.

[0035] It should be noted that the first irradiation channel of the side reflector is usually used for neutron irradiation of the sample to be irradiated. Different samples to be irradiated often have different requirements for the thermal neutron fluence rate. The preset interval can be obtained according to the requirements of the thermal neutron fluence rate of the sample to be irradiated and the safety requirements of the operation of the pebble bed high-temperature gas-cooled reactor.

[0036] In an embodiment of the present application, in response to the first thermal neutron fluence rate being within the preset interval, it indicates that the first thermal neutron fluence rate of the first irradiation channel can meet the requirements of the sample to be irradiated for the thermal neutron fluence rate and the safety requirements of the operation of the pebble bed high-temperature gas-cooled reactor, that is, there is no need to adjust the irradiation channel layout parameters. In response to the first thermal neutron fluence rate of the first irradiation channel not being within the preset interval, it is necessary to adjust the irradiation channel layout parameters. For example, when the first thermal neutron fluence rate is less than the minimum value of the preset interval, the first thermal neutron fluence rate of the first irradiation channel fails to meet the requirements of the sample to be irradiated for the thermal neutron fluence rate. For example, when the first thermal neutron fluence rate is greater than the maximum value of the preset interval, it affects the safety of the operation of the pebble bed high-temperature gas-cooled reactor. Therefore, the irradiation channel layout parameters can be adjusted. For example, at least one of the irradiation channel layout parameters such as the layout position of the irradiation channel, the layout method of the irradiation channel, and the diameter of the irradiation channel is adjusted. According to the adjusted irradiation channel layout parameters, the first irradiation channel is adjusted. After each adjustment, the first thermal neutron fluence rate of the adjusted first irradiation channel is recalculated to achieve multiple optimizations of the first irradiation channel until the thermal neutron fluence rate of the adjusted first irradiation channel is within the preset interval.

[0037] It should be noted that after obtaining the first thermal neutron fluence rate of the first irradiation channel, the first thermal neutron fluence rate can be analyzed. The first thermal neutron fluence rate usually shows a cosine or approximately cosine distribution in the axial direction, with the highest value at the center and gradually decreasing towards both ends, which is a non-uniform irradiation field. By arranging a neutron shield assembly at the axial position of the first irradiation channel, the second irradiation channel after arranging the neutron shield assembly can be obtained. By arranging a neutron shield assembly at the axial position of the first irradiation channel, the uniformity of the thermal neutron fluence rate is achieved to obtain a uniform irradiation field.

[0038] In an embodiment of the present application, the neutron shield assembly layout parameters can be obtained, and according to the neutron shield assembly layout parameters, the neutron shield assembly is arranged at the axial position of the first irradiation channel to obtain the second irradiation channel after arranging the neutron shield assembly.

[0039] It should be noted that the arrangement parameters of the neutron screen assembly include, but are not limited to, the arrangement material and the arrangement thickness of the neutron screen assembly.

[0040] It should be noted that the arrangement material of the neutron screen assembly can utilize the thermal neutron absorption cross-section characteristics of the material. Materials with a larger thermal neutron absorption cross-section can capture thermal neutrons more effectively, thereby reducing the neutron fluence rate. For example: materials containing boron, hafnium, cadmium, etc.

[0041] For example, if the neutron screen assembly uses the same arrangement material, for the area with a high first neutron fluence rate, such as the middle area of the first irradiation channel, increase the arrangement thickness of the neutron screen assembly to enhance the neutron absorption ability and reduce the first thermal neutron fluence rate. For the area with a low first neutron fluence rate, such as the two ends of the first irradiation channel, reduce the arrangement thickness of the neutron screen assembly to reduce the neutron absorption ability.

[0042] For example, if the neutron screen assembly uses different arrangement materials, the arrangement thickness of the neutron screen assembly can remain unchanged. For the area with a high first neutron fluence rate, such as the middle area of the first irradiation channel, select an arrangement material with a larger thermal neutron absorption cross-section to enhance the neutron absorption ability. For the area with a low first neutron fluence rate, such as the two ends of the first irradiation channel, select an arrangement material with a smaller thermal neutron absorption cross-section to reduce the neutron absorption ability.

[0043] In the embodiment of the present application, after obtaining the second irradiation channel after arranging the neutron screen assembly, the second thermal neutron fluence rate of the second irradiation channel can be obtained.

[0044] In the embodiment of the present application, based on the characteristic data of the pebble bed high-temperature gas-cooled reactor, that is, on the basis of the characteristic data such as the core structure and size, fuel enrichment, fuel loading scheme, coolant flow rate of the pebble bed high-temperature gas-cooled reactor, increase the arrangement material and the arrangement thickness of the neutron screen assembly, construct a physical calculation model of the pebble bed high-temperature gas-cooled reactor, call the target calculation program, and based on the physical calculation model of the pebble bed high-temperature gas-cooled reactor, obtain the second thermal neutron fluence rate of the second irradiation channel, where the target calculation program includes at least the VSOP program and / or the MCNP program.

[0045] S403, in response to the second thermal neutron fluence rate satisfying the quasi-uniform distribution, obtain the safety parameters for neutron irradiation of the sample to be irradiated in the second irradiation channel of the side reflector layer of the pebble bed high-temperature gas-cooled reactor.

[0046] In the embodiment of the present application, after obtaining the second thermal neutron fluence rate, it can be determined whether the second thermal neutron fluence rate satisfies the quasi-uniform distribution, and according to the judgment result, it is determined whether to adjust the arrangement parameters of the neutron screen assembly.

[0047] Among them, the second thermal neutron fluence rate satisfies a quasi-uniform distribution, which can be understood as having a slight deviation in the second thermal neutron fluence rate, that is, there is a slight deviation in the second thermal neutron fluence rate along the axis of the second irradiation channel, which can be ignored.

[0048] In the embodiment of the present application, in response to the second thermal neutron fluence rate satisfying the quasi-uniform distribution, it indicates that the second thermal neutron fluence rate of the second irradiation channel can provide a uniform irradiation field, which can meet the uniform irradiation requirements of the sample to be irradiated, that is, there is no need to adjust the arrangement parameters of the neutron shield assembly. In response to the second thermal neutron fluence rate not satisfying the quasi-uniform distribution, it is necessary to adjust the arrangement parameters of the neutron shield assembly. For example: adjust at least one of the arrangement material of the neutron shield assembly and the arrangement thickness of the neutron shield assembly. According to the adjusted arrangement parameters of the irradiation channel, adjust the second irradiation channel, and recalculate the second thermal neutron fluence rate of the adjusted second irradiation channel after each adjustment until the second thermal neutron fluence rate of the adjusted second irradiation channel satisfies the quasi-uniform distribution.

[0049] For example, as Figure 7 shown, if the first thermal neutron fluence rate generally shows a cosine distribution along the axis, which means that the first thermal neutron fluence rate is the highest at the center and gradually decreases towards both ends, so it is a non-uniform irradiation field. By arranging a neutron shield assembly at the axial position of the first irradiation channel, a second irradiation channel with the neutron shield assembly arranged can be obtained. By arranging the neutron shield assembly, the second thermal neutron fluence rate can be adjusted to a uniform distribution (ideally), realizing the flattening of the second thermal neutron fluence rate in the second irradiation channel.

[0050] In the embodiment of the present application, in response to the second thermal neutron fluence rate satisfying the quasi-uniform distribution, the safety parameters for neutron irradiation of the sample to be irradiated in the second irradiation channel of the side reflector layer of the pebble bed high-temperature gas-cooled reactor can be obtained.

[0051] It should be noted that the safety parameters at least include the highest operating temperature of the fuel element, the maximum single-sphere power and the highest accident temperature, the inlet and outlet temperatures of the primary circuit, the excess reactivity and the shutdown depth of the pebble bed high-temperature gas-cooled reactor.

[0052] It should be noted that in response to the second thermal neutron fluence rate satisfying the quasi-uniform distribution, in order to ensure the safety of the pebble bed high-temperature gas-cooled reactor, safety analysis of the pebble bed high-temperature gas-cooled reactor needs to be carried out. The dedicated pebble bed high-temperature gas-cooled reactor safety analysis program TINTE, RELAP can be called, or a combination of different safety analysis programs can be used to obtain operating condition parameters such as the maximum operating temperature of the fuel element, the maximum single-sphere power, and the inlet and outlet temperatures of the primary circuit, as well as accident condition parameters such as the reserve reactivity of the pebble bed high-temperature gas-cooled reactor, the shutdown depth, and the maximum accident temperature of the fuel element. Among them, the safety parameters are used to determine whether the operating safety and accident safety of the pebble bed high-temperature gas-cooled reactor can be ensured when irradiating the sample to be irradiated with neutrons in the second irradiation channel of the side reflector.

[0053] S404. In response to the safety parameters satisfying the safety conditions, the second irradiation channel is used as the target irradiation channel of the side reflector.

[0054] In the embodiment of the present application, in response to the safety parameters satisfying the safety conditions, the second irradiation channel is used as the target irradiation channel of the side reflector. In response to the safety parameters not satisfying the safety conditions, that is, in the case where any safety parameter exceeds the corresponding threshold, the irradiation channel layout parameters and / or the neutron shield assembly layout parameters can be adjusted according to the actual situation of the obtained safety parameters until the adjusted first thermal neutron fluence rate is within the preset interval, the second thermal neutron fluence rate satisfies the quasi-uniform distribution, and the safety parameters satisfy the safety conditions, so as to obtain the final target irradiation channel of the side reflector, which can meet the uniform irradiation of the sample to be irradiated and ensure the safety of the pebble bed high-temperature gas-cooled reactor.

[0055] S405. Based on the target irradiation channel, neutron irradiation is carried out on the sample to be irradiated.

[0056] Among them, the sample to be irradiated is often an isotope or material with high requirements for the uniformity of the thermal neutron fluence rate.

[0057] It should be noted that the target irradiation channel can be understood as a neutron-flattened irradiation channel. The thermal neutron fluence rate in the target irradiation channel is axially flattened. In fact, there are differences in the distribution of the thermal neutron fluence rate in the radial direction of the target irradiation channel. However, since the diameter of the target irradiation channel (about 7 cm) is much smaller than the axial height of the active zone of the pebble bed high-temperature gas-cooled reactor (about 1000 cm), the distribution difference of the thermal neutron fluence rate in the radial direction is much smaller than the axial difference and can be ignored in engineering. In order to achieve uniform irradiation of the sample to be irradiated (irradiation target or material), the present application proposes a neutron irradiation scheme.

[0058] For example, place the sample to be irradiated into the target irradiation channel of the side reflector for neutron irradiation. During the irradiation process, use the irradiation device to rotate the sample to be irradiated circumferentially to reduce the irradiation non-uniformity of the sample to be irradiated in the radial direction, and finally achieve the irradiation uniformity of the sample to be irradiated in the axial and radial directions. At the same time, the sample to be irradiated can be rotated or transposed during the irradiation process, that is, the head and tail of the sample to be irradiated are adjusted to ensure the irradiation uniformity.

[0059] In summary, a method for neutron irradiation of the side reflector of a pebble bed high-temperature gas-cooled reactor proposed in this application obtains the first irradiation channel of the side reflector and the first thermal neutron fluence rate of the first irradiation channel. In response to the first thermal neutron fluence rate being within a preset range, obtain the second irradiation channel after arranging the neutron shield assembly and the second thermal neutron fluence rate of the second irradiation channel. In response to the second thermal neutron fluence rate satisfying a quasi-uniform distribution, obtain the safety parameters for neutron irradiation of the sample to be irradiated in the second irradiation channel of the side reflector of the pebble bed high-temperature gas-cooled reactor. In response to the safety parameters satisfying the safety conditions, use the second irradiation channel as the target irradiation channel of the side reflector, and based on the target irradiation channel, perform neutron irradiation on the sample to be irradiated. Thus, this application realizes the uniform distribution of the thermal neutron fluence rate in the irradiation channel by setting up the irradiation channel in the side reflector of the pebble bed high-temperature gas-cooled reactor and arranging the neutron shield assembly, solves the problem that it is difficult to achieve uniform irradiation in a conventional irradiation channel, and realizes the uniform irradiation of the sample to be irradiated by rotating or transposing the sample to be irradiated, etc., which is feasible, expands the application field of the pebble bed high-temperature gas-cooled reactor, and is beneficial to improving the economy and efficiency.

[0060] Figure 8 It is a schematic structural diagram of a neutron irradiation system for the side reflector of a pebble bed high-temperature gas-cooled reactor according to an embodiment of this application, as Figure 8 shown, a neutron irradiation system 1000 for the side reflector of a pebble bed high-temperature gas-cooled reactor includes a first acquisition module 110, a second acquisition module 120, a third acquisition module 130, a determination module 140, and an irradiation module 150, where:

[0061] The first acquisition module 110 is configured to acquire the first irradiation channel of the side reflector and the first thermal neutron fluence rate of the first irradiation channel;

[0062] The second acquisition module 120 is configured to, in response to the first thermal neutron fluence rate being within a preset range, acquire the second irradiation channel after arranging the neutron shield assembly and the second thermal neutron fluence rate of the second irradiation channel;

[0063] The third acquisition module 130 is configured to, in response to the second thermal neutron fluence rate satisfying a quasi-uniform distribution, acquire the safety parameters for neutron irradiation of the sample to be irradiated in the second irradiation channel of the side reflector of the pebble bed high-temperature gas-cooled reactor,

[0064] A determination module 140, configured to, in response to the security parameter satisfying a security condition, use the second irradiation channel as a target irradiation channel of the side reflector layer;

[0065] An irradiation module 150, configured to perform neutron irradiation on a sample to be irradiated based on the target irradiation channel.

[0066] A side reflector layer neutron irradiation system provided in the second aspect of the present application further has the following technical features.

[0067] According to an embodiment of the present application, a first acquisition module 110 is configured to: acquire irradiation channel layout parameters of the side reflector layer; arrange irradiation channels in the side reflector layer according to the irradiation channel layout parameters to obtain a first irradiation channel of the side reflector layer.

[0068] According to an embodiment of the present application, the system 1000 is further configured to: in response to the first thermal neutron fluence rate not being within a preset interval, adjust the irradiation channel layout parameters; adjust the first irradiation channel according to the adjusted irradiation channel layout parameters until the thermal neutron fluence rate of the adjusted first irradiation channel is within the preset interval.

[0069] According to an embodiment of the present application, the system 1000 is further configured to: for any one of the first thermal neutron fluence rate and the second thermal neutron fluence rate, construct a pebble bed high-temperature gas-cooled reactor physical calculation model according to the characteristic data of the pebble bed high-temperature gas-cooled reactor; call a target calculation program, and based on the pebble bed high-temperature gas-cooled reactor physical calculation model, obtain the any one of the thermal neutron fluence rates, where the target calculation program includes at least a VSOP program and / or an MCNP program.

[0070] According to an embodiment of the present application, a second acquisition module 120 is configured to: acquire neutron shield assembly layout parameters; arrange neutron shield assemblies at the axial positions of the first irradiation channels according to the neutron shield assembly layout parameters to obtain a second irradiation channel after arranging the neutron shield assemblies.

[0071] According to an embodiment of the present application, the system 1000 is further configured to: in response to the second thermal neutron fluence rate not satisfying a quasi-uniform distribution, adjust the neutron shield assembly layout parameters; adjust the neutron shield assemblies according to the adjusted neutron shield assembly layout parameters until the second thermal neutron fluence rate of the adjusted second irradiation channel satisfies the quasi-uniform distribution.

[0072] According to an embodiment of the present application, the system 1000 is further configured to: in response to the safety parameters not meeting the safety conditions, adjust the irradiation channel arrangement parameters and / or the neutron shield assembly arrangement parameters until the adjusted first thermal neutron fluence rate is within a preset range, the second thermal neutron fluence rate meets the quasi-uniform distribution, and the safety parameters meet the safety conditions.

[0073] According to an embodiment of the present application, the safety parameters at least include: the maximum operating temperature of the fuel element, the maximum single-sphere power and the maximum accident temperature, the inlet and outlet temperatures of the primary circuit, the excess reactivity and the shutdown depth of the pebble bed high-temperature gas-cooled reactor.

[0074] In summary, a pebble bed high-temperature gas-cooled reactor side reflector neutron irradiation system proposed in the present application obtains the first irradiation channel of the side reflector, and obtains the first thermal neutron fluence rate of the first irradiation channel. In response to the first thermal neutron fluence rate being within a preset range, it obtains the second irradiation channel after arranging the neutron shield assembly, and obtains the second thermal neutron fluence rate of the second irradiation channel. In response to the second thermal neutron fluence rate meeting the quasi-uniform distribution, it obtains the safety parameters of the pebble bed high-temperature gas-cooled reactor for neutron irradiating a sample to be irradiated in the second irradiation channel of the side reflector. In response to the safety parameters meeting the safety conditions, it uses the second irradiation channel as the target irradiation channel of the side reflector, and based on the target irradiation channel, neutron irradiates the sample to be irradiated. Thus, the present application realizes the uniform distribution of the thermal neutron fluence rate in the irradiation channel by setting up the irradiation channel in the side reflector of the pebble bed high-temperature gas-cooled reactor and arranging the neutron shield assembly, solves the problem that it is difficult to achieve uniform irradiation in a conventional irradiation channel, and realizes the uniform irradiation of the sample to be irradiated by rotating or transposing the sample to be irradiated, etc., which is feasible, expands the application field of the pebble bed high-temperature gas-cooled reactor, and is beneficial to improving the economy and efficiency.

[0075] To implement the above embodiments, the present application also proposes a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the pebble bed high-temperature gas-cooled reactor side reflector neutron irradiation method as described in any one of the above first aspect embodiments.

[0076] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0077] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0078] Any process or method description in a flowchart or described in other ways herein may be understood to represent a module, segment, or portion of code including one or more executable instructions for implementing a customized logic function or process, and the scope of the preferred embodiments of this application includes additional implementations, where the functions may be executed in a substantially simultaneous manner or in a reverse order according to the functions involved, rather than in the order shown or discussed, which should be understood by those skilled in the art to which the embodiments of this application pertain.

[0079] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a definitional sequence of executable instructions for implementing logical functions, and can be embodied specifically in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device. As used in this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of the computer-readable medium include the following: an electrical connection portion having one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable medium on which the program can be printed, as the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpretation, or otherwise processing as appropriate, and then storing it in a computer memory.

[0080] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGA), field programmable gate arrays (FPGA), etc.

[0081] Those of ordinary skill in the art of this technology can understand that all or part of the steps carried by the method of implementing the above embodiments can be completed by a program instructing relevant hardware, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0082] In addition, each functional unit in various embodiments of the present application may be integrated into a processing module, or each unit may exist physically alone, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0083] The above-mentioned storage medium may be a read-only memory, a magnetic disk, an optical disc, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for neutron irradiation of the side reflector layer of a pebble bed high-temperature gas-cooled reactor, characterized in that, The method includes: Obtaining a first irradiation channel of a side reflector layer and obtaining a first thermal neutron fluence rate of the first irradiation channel; In response to the first thermal neutron fluence rate being within a preset interval, obtaining a second irradiation channel after arranging a neutron screen assembly and obtaining a second thermal neutron fluence rate of the second irradiation channel; In response to the second thermal neutron fluence rate satisfying a quasi-uniform distribution, obtaining safety parameters for neutron irradiation of a sample to be irradiated in the second irradiation channel of the side reflector layer of a pebble bed high-temperature gas-cooled reactor; In response to the safety parameters satisfying safety conditions, using the second irradiation channel as the target irradiation channel of the side reflector layer; Based on the target irradiation channel, performing neutron irradiation on the sample to be irradiated.

2. The method according to claim 1, characterized in that, The obtaining of the first irradiation channel of the side reflector layer includes: Obtaining irradiation channel layout parameters of the side reflector layer; According to the irradiation channel layout parameters, arranging an irradiation channel in the side reflector layer to obtain the first irradiation channel of the side reflector layer.

3. The method according to claim 2, characterized in that The method further includes: In response to the first thermal neutron fluence rate not being within the preset interval, adjusting the irradiation channel layout parameters; According to the adjusted irradiation channel layout parameters, adjusting the first irradiation channel until the thermal neutron fluence rate of the adjusted first irradiation channel is within the preset interval.

4. The method according to claim 1, characterized in that The method includes: For any one of the first thermal neutron fluence rate and the second thermal neutron fluence rate, constructing a physical calculation model of a pebble bed high-temperature gas-cooled reactor according to characteristic data of the pebble bed high-temperature gas-cooled reactor; Invoking a target calculation program, and based on the physical calculation model of the pebble bed high-temperature gas-cooled reactor, obtaining the any one thermal neutron fluence rate, where the target calculation program includes at least the VSOP program and / or the MCNP program.

5. The method according to claim 1, wherein The obtaining of the second irradiation channel after arranging the neutron screen assembly includes: Obtaining neutron screen assembly layout parameters; According to the neutron screen assembly layout parameters, arranging a neutron screen assembly at the axial position of the first irradiation channel to obtain the second irradiation channel after arranging the neutron screen assembly.

6. The method according to claim 5, characterized in that, The method further includes: In response to the second thermal neutron fluence rate not satisfying the quasi-uniform distribution, adjusting the neutron screen assembly layout parameters; According to the adjusted neutron screen assembly layout parameters, adjusting the neutron screen assembly until the second thermal neutron fluence rate of the adjusted second irradiation channel satisfies the quasi-uniform distribution.

7. The method according to any one of claims 1-6, characterized in that, The method further includes: In response to the safety parameters not satisfying the safety conditions, adjusting the irradiation channel layout parameters and / or the neutron screen assembly layout parameters until the adjusted first thermal neutron fluence rate is within the preset interval, the second thermal neutron fluence rate satisfies the quasi-uniform distribution, and the safety parameters satisfy the safety conditions.

8. The method according to claim 1, wherein The safety parameters at least include: the maximum operating temperature of a fuel element, the maximum single-sphere power and the maximum accident temperature, the inlet and outlet temperatures of a primary circuit, the excess reactivity and the shutdown margin of the pebble bed high-temperature gas-cooled reactor.

9. A neutron irradiation system for the side reflector of a pebble bed high temperature gas cooled reactor, characterized in that, The system includes: A first acquisition module for obtaining a first irradiation channel of a side reflector layer and obtaining a first thermal neutron fluence rate of the first irradiation channel; A second acquisition module, configured to acquire a second irradiation channel after arranging a neutron shield assembly and acquire a second thermal neutron fluence rate of the second irradiation channel in response to the first thermal neutron fluence rate being within a preset range; A third acquisition module, configured to acquire safety parameters for neutron irradiation of a sample to be irradiated in a second irradiation channel of a pebble bed high temperature gas-cooled reactor in a side reflector in response to the second thermal neutron fluence rate satisfying a quasi-uniform distribution; A determination module, configured to use the second irradiation channel as the target irradiation channel of the side reflector in response to the safety parameters satisfying safety conditions; An irradiation module, configured to perform neutron irradiation on the sample to be irradiated based on the target irradiation channel.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method for neutron irradiation of a side reflector of a pebble bed high temperature gas-cooled reactor according to any one of claims 1-8.

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