Calculation method and device for fine power of small irradiation component in research reactor and readable storage medium

Abstract

The invention relates to a fine power calculation method and device for researching a small irradiation component in a reactor and a readable storage medium. The fine power calculation method comprises the following steps: S1, acquiring parameter information of a structural component in a reactor core; s2, dividing the structural component into a plurality of homogenized grids and dividing a neutron transport calculation area; s3, calculating neutron fluence rate and power in each region; s4, calculating a power weight factor of each fuel rod; s5, judging whether all state calculation of the structural component is completed or not, and if yes, entering the step S7; s6, changing the state parameter information of the structure assembly, and calculating the neutron fluence rate and power, the homogenization cross section, the homogenization grid geometric information and the power weight factor; s7, calculating the neutron fluence rate and power of the three-dimensional fine net of the reactor core; and S8, calculating the three-dimensional power of each fuel rod of the irradiation small component. According to the method, the calculation resolution of the irradiation small component can be improved, and the safety analysis capability of the irradiation small component is improved.

Description

Technical Field

[0001] The present invention relates to the field of reactor engineering design technology, and in particular to a method, a device and a readable storage medium for calculating the fine power of irradiated small components in a research reactor. Background Art

[0002] Research reactors use neutrons, photons and other radiation beams generated by controlled chain fission reactions for research and application work such as fuel / material irradiation testing, radioisotope production, and neutron analysis. They are important scientific research infrastructure for promoting the development of advanced nuclear energy and nuclear technology, and play a very important supporting role in the development of advanced reactor technology, the supply of medical and industrial isotopes, nuclear medicine, materials science, and life sciences. Plate fuel has a larger area-to-volume ratio and a larger heat exchange area, making it more suitable for research reactors that require high power density and high neutron injection rate.

[0003] One of the key uses of research reactors is the irradiation test of reactor fuel, which can provide important data support for reactor fuel design. In order to obtain a larger neutron injection rate, the fuel irradiation channel is usually arranged inside the research reactor. During the experiment, the irradiation small component is placed in the fuel irradiation channel. The parameters such as the power peak factor and burnup characteristics of the irradiation small component will greatly test the nuclear design of the research reactor irradiation test loop.

[0004] At present, the international community usually adopts the "three-step method" and "two-step method" for calculations of plate-fuel research reactors. However, due to the component homogenization process, this type of program will actually lose information in the irradiated small components during the core calculation process, making it difficult to obtain accurate power and fuel consumption distribution of different fuel rods in the irradiated small components. It is also impossible to calculate key safety parameters such as the power peak factor and radial power non-uniformity factor in the irradiated small components. Therefore, a larger safety margin needs to be considered in the irradiation channel design process. Summary of the invention

[0005] In view of the above-mentioned problems in the prior art, the present invention proposes a method, device and readable storage medium for calculating the fine power of irradiated small components in a research reactor, which can improve the calculation resolution of irradiated small components, improve the safety analysis capability of irradiated small components, reduce the uncertainty in the design of irradiation channels, and improve the economy and safety of the irradiation channel design process.

[0006] Specifically, the present invention proposes a method for calculating the fine power of irradiated small components in a research reactor, comprising the steps of:

[0007] S1, obtaining parameter information of multiple structural components in the core, wherein the multiple structural components include a plate-shaped fuel assembly, a reflector assembly, and an irradiation subassembly, and the parameter information includes geometric dimensions, material arrangement information, and state parameter information;

[0008] S2, based on the parameter information, dividing the plate-shaped fuel assembly, the irradiation subassembly and the reflector assembly into a plurality of uniform grids, obtaining geometric information of the uniform grids, and further dividing a neutron transport calculation region in each of the uniform grids;

[0009] S3, calculating the neutron fluence rate and power in each of the neutron transport calculation areas based on the parameter information;

[0010] S4, calculating the homogenized cross section in each of the homogenized grids based on the neutron fluence rate and power in each of the neutron transport calculation regions; and calculating the power weight factor of each fuel rod in the irradiated subassembly;

[0011] S5, judging whether all state calculations of the structural components are completed, if yes, proceeding to step S7; if not, proceeding to step S6;

[0012] S6, changing the state parameter information of the structural component, returning to step S3, thereby calculating the neutron fluence rate and power in the neutron transport calculation area under different state parameter information, the homogenized cross section in each homogenized grid, and the power weight factor of each fuel rod in the irradiated subassembly;

[0013] S7, obtaining core parameter information of the core, dividing the core into a plurality of calculation grids based on the core parameter information, geometric information of the uniformized grid and the calculation result of step S5, establishing a neutron diffusion equation of the core, and calculating the power of the three-dimensional fine grid of the core;

[0014] S8, based on the core position of the irradiated small assembly and the power of the three-dimensional fine mesh of the core, determine the power of the three-dimensional fine mesh corresponding to its position, and calculate the three-dimensional power of each fuel rod of the irradiated small assembly according to the power weight factor of each fuel rod in the irradiated small assembly.

[0015] According to one embodiment of the present invention, the fine power calculation method further includes:

[0016] S9, calculating the heat flux heat pipe factor and the enthalpy rise heat pipe factor in the irradiation subassembly based on the three-dimensional power of each of the fuel rods;

[0017] S10, calculating a detailed burnup distribution in the irradiated small assembly based on the three-dimensional power of each of the fuel rods and the mass of heavy nuclei in the homogenized cross sections in all the homogenized grids.

[0018] According to one embodiment of the present invention, the state parameter information of the plate-shaped fuel assembly and the irradiated small assembly includes average burnup depth, fuel temperature, moderator temperature and assembly power density, and the state parameter information of the reflector layer assembly includes fuel temperature, moderator temperature and assembly power density.

[0019] According to one embodiment of the present invention, in step S2, the irradiated small component and its adjacent structures are defined as a generalized component area, the generalized component area is divided into a number of uniformized grids, and a neutron transport calculation area is further divided in each of the uniformized grids; the reflective layer component and the adjacent structures are defined as a generalized component area, the generalized component area is divided into a number of uniformized grids, and a neutron transport calculation area is further divided in each of the uniformized grids.

[0020] According to an embodiment of the present invention, in step S3, a numerical method is used to calculate the neutron fluence rate and power in each of the neutron transport calculation regions, and the numerical method includes a characteristic line method and a collision probability method.

[0021] According to one embodiment of the present invention, in step S4, the calculation formula of the power weight factor of each fuel rod in the irradiation subassembly is:

[0022]

[0023] Among them, c i,weight represents the power weight factor of the i-th fuel rod in the irradiation subassembly, P m,i represents the power of the i-th fuel rod in the m-th calculation area where the irradiated small component is located, obtained by solving the neutron transport solution of the component, P m Represents the power of the mth calculation area where the irradiated small component is located, obtained by solving the neutron transport solution of the component.

[0024] According to one embodiment of the present invention, in step S7, the core parameter information of the core includes component layout information, radial and axial material information, core power level, control rod position, moderator inlet temperature and the radial position of the core where the irradiated subassembly is located.

[0025] According to one embodiment of the present invention, in step S8, the calculation formula for the three-dimensional power of each fuel rod of the irradiated small assembly is:

[0026] P loop,i,iz =c i,weig h t P imes h;

[0027] Among them, P loop,i,iz represents the power of irradiating the axial layer z of the i-th fuel rod of the small assembly, P imesh represents the imeshth fine mesh power of the core where the axial izth layer of the irradiated small component is located, obtained by solving the core neutron diffusion problem.

[0028] According to one embodiment of the present invention, in step S9, the calculation formulas of the heat flux heat pipe factor and the enthalpy rise heat pipe factor in the irradiated small component are:

[0029]

[0030] Among them, F Q The heat pipe factor, F, represents the heat flux density. Δ h represents the enthalpy rise heat pipe factor, P loop,i,iz represents the power of the axial layer z of the ith fuel rod of the irradiated small assembly, P ave Represents the average power density of all irradiated components, L iz represents the size of the axial grid where the iz layer of the ith irradiated small component is located, ∑ iz P loop,i,iz represents the axial integrated power of the i-th fuel rod of the irradiated small assembly, ∑ iz L iz Indicates the size of the axial grid where the iz layer of the irradiated small component is located.

[0031] According to one embodiment of the present invention, in step S10, the calculation formula for the fine burnup distribution in the irradiated small component is:

[0032]

[0033] Among them, n,i,iz represents the burnup depth of the iz layer of the ith irradiated small component in the nth step, P loop,i,iz represents the power of the iz layer of the ith irradiated small component, Δt n represents the fuel consumption step length of the nth step, M U,i,iz represents the mass of heavy nuclei in the iz layer of the ith irradiated small component.

[0034] The present invention also provides a device for calculating the fine power of irradiated small components in a research reactor, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any of the aforementioned methods for calculating fine power when executing the computer program.

[0035] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above-mentioned methods for calculating fine power are implemented.

[0036] The present invention provides a method, device and readable storage medium for calculating the fine power of irradiated small components in a research reactor. A construction geometry method is combined with a component modeling method to obtain a fine model of the component, and the three-dimensional fine power distribution and burnup distribution of each fuel rod in the irradiated small component are calculated to obtain key safety parameters such as the heat flux density heat pipe factor and the nuclear enthalpy rise heat pipe factor in the irradiated small component, thereby significantly improving the calculation resolution of the irradiated small component and the safety analysis capability of the irradiated small component, reducing the uncertainty in the design of the irradiation channel, and improving the economy and safety in the irradiation channel design process.

[0037] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are included to provide further explanation of the present invention, and are incorporated into and constitute a part of this application. The accompanying drawings illustrate embodiments of the present invention and together with the description serve to explain the principle of the present invention.

[0039] In the attached figure:

[0040] Figure 1 A flowchart of a method for calculating the fine power of an irradiated small component in a research reactor according to an embodiment of the present invention is shown.

[0041] Figure 2 A flowchart of a method for calculating the fine power of an irradiated small component in a research reactor according to another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0042] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0043] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0045] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0046] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0047] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0048] Figure 1A flowchart of a method for calculating the fine power of a small irradiated component in a research reactor according to an embodiment of the present invention is shown. As shown in the figure, a method for calculating the fine power of a small irradiated component in a research reactor comprises the following steps:

[0049] S1, obtain parameter information of multiple structural components in the core. Multiple structural components include plate fuel assemblies, reflector assemblies and irradiation subassemblies. The parameter information includes the geometric dimensions, material layout information and state parameter information of each structural component. It should be noted that the plate fuel assembly is the energy source of the core. Its fissionable material undergoes fission to produce a large amount of energy and conducts heat away. At the same time, its composition and state will also affect the reactivity. The irradiation subassembly is mainly used for material irradiation research, production of radioactive isotopes, and neutron analysis experiments. The reflector assembly reflects the neutrons scattered out of the core back to improve the neutron utilization rate. It can also adjust the core neutron flux distribution to make it more uniform. In addition, it can also help reduce the number of neutrons radiated outward from the core and play a certain protective role.

[0050] S2, based on the parameter information of each structural component, the plate-shaped fuel assembly, irradiation subassembly and reflector assembly are divided into several uniform grids, the geometric information of the uniform grids is obtained, and the neutron transport calculation area is further divided in each uniform grid. Specifically, each structural component is divided into several uniform grids of appropriate size and uniform distribution according to the characteristics of its geometric shape, material distribution and state parameter information, and the corresponding geometric information is obtained. The divided uniform grids should be fine enough. In these grids, the transport characteristics and interactions of neutrons in each structural component are fully considered, and the neutron transport calculation area is further accurately divided, so as to accurately simulate and calculate the behavior and influence of neutrons in the structural components.

[0051] S3, based on the parameter information of each structural component, calculate the neutron injection rate and power in the neutron transport calculation area according to the boundaries of each neutron transport calculation area and the nuclide composition of each structural component. Among them, the nuclide composition of the plate fuel assembly refers to the types of various radioactive nuclides and stable nuclides that constitute the plate fuel assembly and their relative contents. These nuclides play a key role in many aspects such as the performance of the plate fuel assembly, the nuclear reaction process and the radioactive characteristics. The nuclide composition of the irradiation subassembly refers to the various types of nuclides contained in the irradiation subassembly and their relative contents. These nuclides play a role in the irradiation process, and the change of their composition will have an important impact on many aspects such as the irradiation effect, the change of material properties and the generation of radioactive isotopes. The nuclide composition of the reflector assembly refers to the types of various nuclides that constitute the reflector assembly and their proportions in it. Its nuclide composition is crucial to the neutron reflection efficiency, the core neutron flux distribution and the overall performance of the reactor.

[0052] S4, based on the neutron injection rate and power in each neutron transport calculation area, comprehensively consider the interaction process between neutrons and matter, calculate the homogenized cross section in each homogenized grid, so as to more effectively describe the characteristics of the material in the homogenized grid to neutrons. At the same time, for the irradiated small assembly, according to its internal structure and neutron distribution, etc., calculate the power weight factor of each fuel rod in the irradiated small assembly, and determine the power contribution ratio of each fuel rod in the irradiated small assembly.

[0053] S5, judging whether all state calculations of the structural components are completed, if yes, proceeding to step S7; if not, proceeding to step S6;

[0054] S6, changing the state parameter information of the structural component, returning to step S3, thereby calculating the neutron injection rate and power in the neutron transport calculation area under different state parameter information, the homogenized cross section in each homogenized grid, and the power weight factor of each fuel rod in the irradiated small component. Through steps S3 to S6, the nuclear physical characteristics and performance of each structural component under different state parameter information are fully understood.

[0055] S7, obtain the core parameter information of the core, and divide the core into several calculation grids based on the core parameter information, the geometric information of the uniformized grid, the neutron injection rate and power in the neutron transport calculation area under different state parameter information, the uniformized cross section in each uniformized grid, the uniformized grid geometric information and the power weight factor of each fuel rod in the irradiated small assembly. On the basis of the calculation grid, establish a neutron diffusion equation that can accurately describe the neutron behavior in the core, and calculate the three-dimensional fine grid power of the core. Among them, the core parameter information includes the layout of each structural component, radial and axial material information, core power level, control rod position and moderator inlet temperature, as well as the radial position and parameter information of the core where the irradiated small assembly is located.

[0056] S8, based on the core position of the irradiated small assembly and the three-dimensional fine-grid power of the core, determine the three-dimensional fine-grid power corresponding to its position. This process needs to consider the complexity and unevenness of the neutron distribution inside the core to ensure the accuracy of positioning. According to the power weight factor of each fuel rod in the irradiated small assembly, calculate the three-dimensional power of each fuel rod in the irradiated small assembly. The three-dimensional power fully reflects the energy output of the fuel rod.

[0057] Figure 2 A flowchart of another embodiment of the present invention is shown for a method for calculating the fine power of a small component irradiated in a research reactor. As shown in the figure, the fine power calculation method also includes:

[0058] S9, based on the three-dimensional power of each fuel rod, considering the principle of heat conduction and the energy transfer process in the fuel rod, calculate the heat flux heat pipe factor in the irradiated subassembly. The heat flux heat pipe factor reflects the non-uniformity of the heat flux. At the same time, according to the law of conservation of energy and thermodynamics, calculate the enthalpy rise heat pipe factor. The enthalpy rise heat pipe factor is used to evaluate the non-uniformity of enthalpy rise.

[0059] S10, calculates the fine burnup distribution in the irradiated subassembly based on the 3D power of each fuel rod and the mass of heavy nuclei in the homogenized sections in all homogenized grids. The mass of heavy nuclei refers to the sum of the masses of the atomic nuclei with larger mass numbers in the structural assembly. During the nuclear reaction, the change in the mass of heavy nuclei can reflect the consumption of fuel. As the irradiation process progresses, the mass of heavy nuclei will increase due to the absorption of neutrons. These mass changes are key factors in calculating the fine burnup distribution, etc., indicating the consumption and conversion of fuel in the irradiated subassembly.

[0060] In some examples, the state parameter information of the plate-shaped fuel assembly and the irradiated small assembly includes the average burnup depth, fuel temperature, moderator temperature and assembly power density. The state parameter information of the reflector assembly includes the fuel temperature, moderator temperature and assembly power density.

[0061] In some examples, in step S2, the irradiated small component and its adjacent structures are defined as a generalized component region, the generalized component region is divided into a number of homogenized grids, and a neutron transport calculation region is further divided in each homogenized grid to accurately simulate the transport behavior and interaction of neutrons in the region. Similarly, the reflector component and the adjacent structures are defined as a generalized component region, the generalized component region is divided into a number of homogenized grids, and a neutron transport calculation region is further divided in each homogenized grid to accurately simulate the transport behavior and interaction of neutrons in the region.

[0062] In some examples, in step S3, a numerical method is used to calculate the neutron fluence rate and power in each neutron transport calculation region, and the numerical method includes a characteristic line method and a collision probability method. The characteristic line method performs calculations by analyzing the characteristics of the neutron motion trajectory, and the collision probability law is solved based on the probability of the interaction between neutrons and matter, so as to accurately obtain the neutron fluence rate and power in each neutron transport calculation region.

[0063] In some examples, in step S4, a super homogenization method is used to obtain homogenized cross sections in all homogenized grids in each structural component. The super homogenization method is suitable for detailed analysis and processing of complex structures, so that the cross-sectional data of each homogenized grid can ensure the conservation of various physical quantities during the core diffusion calculation process.

[0064] In some examples, at step S4, a volume weight method is used to calculate the power weight factor of each fuel rod in the irradiated subassembly, and the calculation formula is:

[0065]

[0066] Among them, c i,weight represents the power weight factor of the i-th fuel rod in the irradiation subassembly, P m,i represents the power of the i-th fuel rod in the m-th calculation area where the irradiated small component is located, obtained by solving the neutron transport solution of the component, P m Represents the power of the mth calculation area where the irradiated small component is located, obtained by solving the neutron transport solution of the component.

[0067] In some examples, in step S7, the core parameter information of the reactor core includes component layout information, radial and axial material information, core power level, control rod position, moderator inlet temperature, and radial position of the core where the irradiated small component is located. The core parameter information of the reactor core also includes parameter information of each structural component.

[0068] In some examples, in step S7, after establishing the neutron diffusion equation of the three-dimensional core, the fine-grid finite difference method is used to calculate the fine-grid power.

[0069] In some examples, at step S8, the three-dimensional power of each fuel rod of the irradiated small assembly is calculated by:

[0070] P loop,i,iz =c i,weig h t P imes h;

[0071] Among them, P loop,i,iz represents the power of irradiating the axial layer z of the i-th fuel rod of the small assembly, P imes h represents the imeshth fine mesh power of the core where the axial izth layer of the irradiated small component is located, obtained by solving the core neutron diffusion problem.

[0072] In some examples, in step S9, the heat flux heat pipe factor and the enthalpy rise heat pipe factor in the irradiated small component are calculated as follows:

[0073]

[0074] Among them, F Q The heat pipe factor, F, represents the heat flux density. Δ h represents the enthalpy rise heat pipe factor, P loop,i,iz represents the power of the axial layer z of the ith fuel rod of the irradiated small assembly, P abe Represents the average power density of all irradiated components, L izrepresents the size of the axial grid where the iz layer of the ith irradiated small component is located, ∑ iz P loop,i,iz represents the axial integrated power of the i-th fuel rod of the irradiated small assembly, ∑ iz L iz Indicates the size of the axial grid where the iz layer of the irradiated small component is located.

[0075] In some examples, in step S10, the calculation formula for the fine burnup distribution in the irradiated small component is:

[0076]

[0077] Among them, n,i,iz represents the burnup depth of the iz layer of the ith irradiated small component in the nth step, P loop,i,iz represents the power of the iz layer of the ith irradiated small component, Δt n represents the fuel consumption step length of the nth step, M U,i,iz represents the mass of heavy nuclei in the iz layer of the ith irradiated small component.

[0078] The present invention also provides a device for calculating the fine power of irradiated small components in a research reactor, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any of the steps of the aforementioned method for calculating the fine power of irradiated small components in a research reactor.

[0079] The present invention also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, any of the steps of the aforementioned method for calculating the fine power of irradiated small components in a research reactor is implemented.

[0080] Among them, the specific implementation methods and technical effects of the device for calculating the fine power of small components irradiated in the research reactor and the computer-readable storage medium can be referred to the embodiment of the method for calculating the fine power of small components irradiated in the research reactor provided by the above-mentioned present invention, which will not be repeated here.

[0081] The present invention provides a method for calculating the fine power of a small irradiated component in a research reactor, a device for calculating the fine power of a small irradiated component in a research reactor, and a readable storage medium, which have the following beneficial effects:

[0082] (1) Taking into full consideration the fuel assembly, irradiation subassembly, and complex reflector assembly around the core, a multi-component modeling method is used to directly establish a fine component model, divide the structural components into fine uniform grids, and then calculate the precise small group constants of each fine grid, which can accurately reflect the behavior of neutrons in the medium, thus solving the problem of uniform calculation of irradiation subassemblies caused by the high leakage characteristics of irradiation subassemblies around the core;

[0083] (2) The power weight factor of the irradiated small assembly is calculated and combined with the fine-grid neutron injection rate obtained from the core calculation, the three-dimensional power and fine burnup distribution of each fuel rod in the irradiated small assembly can be calculated accurately, thereby improving the calculation accuracy of the irradiated small assembly and reducing the uncertainty in subsequent safety analysis.

[0084] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or a combination of the two. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. The technician may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as resulting in a departure from the scope of the present invention.

[0085] The various illustrative logic modules and circuits described in conjunction with the embodiments disclosed herein may be implemented or executed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in cooperation with a DSP core, or any other such configuration.

[0086] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read and write information from / to the storage medium. In an alternative, a storage medium may be integrated into a processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and the storage medium may reside in a user terminal as discrete components.

[0087] In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented as a computer program product in software, each function may be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, including any medium that facilitates the transfer of a computer program from one place to another. Storage media may be any available medium that can be accessed by a computer. As an example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of an instruction or data structure and can be accessed by a computer. Any connection is also properly referred to as a computer-readable medium. For example, if the software is transmitted from a website, a server, or other remote source using a coaxial cable, a fiber optic cable, a twisted pair, a digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of the medium. Disk and disc as used herein include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, wherein disk often reproduces data magnetically, while disc reproduces data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0088] It will be apparent to those skilled in the art that various modifications and variations may be made to the above exemplary embodiments of the present invention without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention covers modifications and variations of the present invention that fall within the scope of the appended claims and their equivalent technical solutions.

Claims

1. A method for calculating the fine power of irradiated small components in a research reactor, comprising the steps of: S1, obtaining parameter information of multiple structural components in the core, wherein the multiple structural components include a plate-shaped fuel assembly, a reflector assembly, and an irradiation subassembly, and the parameter information includes geometric dimensions, material arrangement information, and state parameter information; S2, based on the parameter information, dividing the plate-shaped fuel assembly, the irradiation subassembly and the reflector assembly into a plurality of uniform grids, obtaining geometric information of the uniform grids, and further dividing a neutron transport calculation region in each of the uniform grids; S3, calculating the neutron fluence rate and power in each of the neutron transport calculation areas based on the parameter information; S4, calculating a homogenized cross section in each of the homogenized grids based on the neutron fluence rate and power in each of the neutron transport calculation regions; Calculating a power weight factor for each fuel rod in the irradiation subassembly; S5, judging whether all state calculations of the structural components are completed, if yes, proceeding to step S7; if not, proceeding to step S6; S6, changing the state parameter information of the structural component, returning to step S3, thereby calculating the neutron fluence rate and power in the neutron transport calculation area under different state parameter information, the homogenized cross section in each homogenized grid, and the power weight factor of each fuel rod in the irradiated subassembly; S7, obtaining core parameter information of the core, dividing the core into a plurality of calculation grids based on the core parameter information, geometric information of the uniformized grid and the calculation result of step S5, establishing a neutron diffusion equation of the core, and calculating the three-dimensional fine grid power of the core; S8, based on the core position of the irradiated small assembly and the three-dimensional fine mesh power of the core, determine the power of the three-dimensional fine mesh corresponding to its position, and calculate the three-dimensional power of each fuel rod in the irradiated small assembly according to the power weight factor of each fuel rod.

2. The fine power calculation method according to claim 1, characterized in that: Also includes: S9, calculating the heat flux heat pipe factor and the enthalpy rise heat pipe factor in the irradiation subassembly based on the three-dimensional power of each of the fuel rods; S10, calculating a detailed burnup distribution in the irradiated small assembly based on the three-dimensional power of each of the fuel rods and the mass of heavy nuclei in the homogenized cross sections in all the homogenized grids.

3. The fine power calculation method according to claim 1, characterized in that: The state parameter information of the plate-shaped fuel assembly and the irradiated small assembly includes average burnup depth, fuel temperature, moderator temperature and assembly power density, and the state parameter information of the reflector layer assembly includes fuel temperature, moderator temperature and assembly power density.

4. The fine power calculation method according to claim 1, characterized in that: In step S2, the irradiated small component and its adjacent structure are defined as a generalized component area, the generalized component area is divided into a number of uniformized grids, and a neutron transport calculation area is further divided in each of the uniformized grids; the reflector layer component and its adjacent structure are defined as a generalized component area, the generalized component area is divided into a number of uniformized grids, and a neutron transport calculation area is further divided in each of the uniformized grids.

5. The fine power calculation method according to claim 1, characterized in that: In step S3, a numerical method is used to calculate the neutron fluence rate and power in each of the neutron transport calculation regions, wherein the numerical method includes a characteristic line method and a collision probability method.

6. The fine power calculation method according to claim 1, characterized in that: In step S4, the power weight factor of each fuel rod in the irradiated subassembly is calculated as follows: Among them, c i,weight represents the power weight factor of the i-th fuel rod in the irradiation subassembly, P m,i represents the power of the i-th fuel rod in the m-th calculation area where the irradiated small component is located, obtained by solving the neutron transport solution of the component, P m Represents the power of the mth calculation area where the irradiated small component is located, obtained by solving the neutron transport solution of the component.

7. The fine power calculation method according to claim 1, characterized in that: In step S7, the core parameter information of the core includes component layout information, radial and axial material information, core power level, control rod position, moderator inlet temperature and the core radial position of the irradiated small component.

8. The fine power calculation method according to claim 6, characterized in that: In step S8, the calculation formula of the three-dimensional power of each fuel rod of the irradiated small assembly is: P loop,i,iz =c i,weig h t P imes h; Among them, P loop,i,iz represents the power of irradiating the axial layer z of the i-th fuel rod of the small assembly, P imesh It represents the imeshth fine mesh power of the core where the axial iz layer of the irradiated small component is located, obtained by solving the core neutron diffusion solution.

9. The fine power calculation method according to claim 2, characterized in that: In step S9, the calculation formulas for the heat flux heat pipe factor and the enthalpy rise heat pipe factor in the irradiated small component are: Among them, F Q The heat pipe factor, F, represents the heat flux density. Δh represents the enthalpy rise heat pipe factor, P loop,i,iz represents the power of the axial layer z of the ith fuel rod of the irradiated small assembly, P ave Represents the average power density of all irradiated components, L iz represents the size of the axial grid where the iz layer of the ith irradiated small component is located, ∑ iz P loop,i,iz represents the axial integrated power of the i-th fuel rod of the irradiated small assembly, ∑ iz L iz Indicates the size of the axial grid where the iz layer of the irradiated small component is located.

10. The fine power calculation method according to claim 9, characterized in that: In step S10, the calculation formula for the fine burnup distribution in the irradiated small component is: Among them, n,i,iz represents the burnup depth of the iz layer of the ith irradiated small component in the nth step, P loop,i,iz represents the power of the iz layer of the ith irradiated small component, Δt n represents the fuel consumption step length of the nth step, M U,i,iz represents the mass of heavy nuclei in the iz layer of the ith irradiated small component.

11. A device for calculating the fine power of irradiated small components in a research reactor, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the fine power calculation method according to any one of claims 1 to 10 are implemented.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the fine power calculation method according to any one of claims 1 to 10 are implemented.

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