A nuclear simulation analysis system and method

Abstract

The present invention belongs to the field of nuclear design and safety analysis based on comprehensive neutron physics computational simulation in nuclear science, and particularly relates to a nuclear simulation analysis system and method. The system includes a geometry modeling module, a physics modeling module, a neutron transport modeling module, a neutronics multi-physics coupling modeling module, and a processing module. The significance of the present invention lies in that an integrated computational model for comprehensive simulation of different physical processes can be constructed based on a unified framework, the real physical processes can be fully considered, and the mutual correlation effects between various physical processes in dimensions such as space, energy, and time can be accurately reflected, so as to better serve nuclear simulation analysis.

Description

Technical Field

[0001] The present invention belongs to the field of nuclear design and safety analysis based on comprehensive computational simulation of neutron physics in nuclear science, and particularly relates to a nuclear simulation analysis system and method. Background Art

[0002] Neutronics theory studies the motion of neutrons in a medium and the nuclear reaction process, that is, the neutron transport process, which is the basis and core of neutronics research. Neutron transport includes processes such as neutron motion, nuclide transmutation, and energy deposition. Among them, neutron motion studies the motion law of neutrons in a medium, including steady-state neutron transport and time-dependent neutron motion. Time-dependent neutron motion is further divided into three types: short-time (millisecond to second) neutron motion process, medium-time (hour to day) neutron motion process, and long-time (month to year) neutron motion process. The short-time neutron motion process considers the impact of expected or accidental changes in the nuclear energy system on neutron motion, resulting in a rapid change in neutron flux density within the system, which is the content of neutron dynamics research; the medium-time and long-time neutron motion processes consider the impact of nuclide changes (such as changes in burnable poisons, nuclide burnup changes, etc.) brought about by nuclide transmutation (including processes such as burnup, nuclear waste transmutation, nuclear fuel breeding, and material activation) on neutron motion. Energy deposition studies the process of converting the kinetic energy of neutrons and the energy released during nuclear reactions into heat energy when neutrons move in a medium, which is the basis for power generation in nuclear energy systems and is also the main factor causing human radiation dose hazards and irradiation damage to devices.

[0003] The nuclear simulation analysis of nuclear energy systems not only involves neutron transport processes such as neutron motion, nuclide transmutation, and energy deposition, but also involves the interaction between neutron transport and multiple physics such as thermal-hydraulics, structural mechanics, chemistry, biology, and electromagnetics (referred to as "neutronics multi-physics coupling"). These physical processes interact with each other and are interrelated, showing extremely strong complexity. In nuclear energy systems, nuclear fission reactions occurring between neutrons and fissile nuclides and nuclear fusion reactions occurring when light atomic nuclei (such as deuterium and tritium) collide will generate neutrons and release energy. Neutrons move in the entire spatial structure of the nuclear energy system and trigger the process of nuclide transmutation (such as nuclear waste transmutation, nuclear fuel breeding, nuclear fuel consumption, activation of structural materials and coolants, etc.). At the same time, the change in nuclide density caused by transmutation will affect the neutron motion process at the next moment. The radioactive nuclides generated by nuclide transmutation triggered by neutrons leaking into the environment may cause radiation exposure to organisms and pose hazards. In addition, the energy carried by neutrons is deposited in the nuclear energy system, and heat is carried out for power generation through the heat transfer of the coolant flow. During the coolant flow heat transfer process, the coolant scours and corrodes the structural materials. At the same time, the temperature and density changes of the coolant and the deformation and density changes of the structural materials will also affect the neutron motion process.

[0004] Therefore, nuclear simulation analysis of nuclear energy systems requires studying the process of neutrons interacting with matter in the entire nuclear energy system. Establishing a sophisticated full-space integrated and accurate model that includes all components of the nuclear energy system, the building environment, and site operators is an important basis for simulation analysis of nuclear energy systems. The model complexity of nuclear energy systems is mainly reflected in two aspects:

[0005] (1) There are a large number of irregular geometric bodies with complex shapes in the model. The number of boundary surfaces that make up the geometric bodies is large and includes high-order complex surfaces such as B-spline surfaces and swept surfaces. Traditional modeling methods have low accuracy, are time-consuming, non-intuitive, and prone to errors.

[0006] (2) The number of geometric bodies in the model is huge and the logical structure is complex. There are large differences in the geometries in different regions, and the model parameters need to be repeatedly modified. The traditional conversion modeling method has problems such as high hardware resource consumption, long conversion time, and a large amount of redundant information in the converted geometry, resulting in low computational efficiency.

[0007] In addition, the traditional discrete and isolated solution method forces the decoupling of many originally interrelated processes and physical phenomena, and each link is solved independently. After the calculation of one link is completed, the calculation result data of its space, energy, time and other dimensions are passed to another link, resulting in low simulation accuracy and difficulty in accurately describing the comprehensive characteristics of the system. This is reflected in the modeling process, that is, each physical process is modeled independently and has no correlation with each other, resulting in the need to frequently exchange data between different programs during the calculation process, resulting in time and precision loss. At the same time, because their spatial discretization schemes are usually inconsistent, data mapping and interpolation must be performed between the two sets of spatial discretization schemes, which is a very time-consuming task and will also result in a certain loss of precision and may also destroy the conservation of physical quantities. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a nuclear simulation analysis system and method.

[0009] The technical solution of the present invention to solve the above technical problems is as follows: a nuclear simulation analysis system, comprising: a geometric modeling module, a physical modeling module, a neutron transport modeling module, a neutronics multi-physics coupling modeling module and a processing module;

[0010] The geometric modeling module is used to traverse the high-order surfaces in each geometric model used in the nuclear simulation analysis, perform triangulation processing on each high-order surface based on a preset patching accuracy, and associate the number of each geometric model with the corresponding patching result;

[0011] The physical modeling module is used to set neutron source parameters for the neutron source in each geometric model;

[0012] The neutron transport modeling module is used to set transport parameters for each geometric model;

[0013] The neutronics multi - physical coupling modeling module is used to perform clipping processing on the original surface in each geometric model through the parametric surface solid clipping method to obtain the mapping relationship between the grids of each geometric model and thermal - hydraulic and structural mechanics;

[0014] The processing module is used to perform nuclear simulation analysis based on the meshing processing results of each geometric model, the neutron source parameter setting results of each geometric model, the transport parameter setting results of each geometric model, and each mapping relationship.

[0015] The beneficial effects of the present invention are as follows: The significance of the present invention lies in that it can construct an integrated calculation model for comprehensive simulation of different physical processes based on a unified framework, fully consider the real physical process, accurately reflect the interaction between physical processes in dimensions such as space, energy, and time, so as to better serve nuclear simulation analysis, and perform design optimization or safety evaluation processing on nuclear energy systems or nuclear technology application systems based on the nuclear simulation analysis results.

[0016] Based on the above - mentioned technical solution, the present invention can be further improved as follows.

[0017] Further, the geometric modeling module is further used for:

[0018] When the boundary surface equation of the geometric model can be expressed by an analytical function, associate the number of the geometric model with the analytical function of the geometric model;

[0019] Or when the boundary surface of the geometric model is a high - order surface, associate the number of the geometric model with the meshing processing result of the geometric model.

[0020] Further, the neutron source parameters include:

[0021] The position distribution, energy spectrum, and angular distribution of the neutron source term.

[0022] Further, the process of setting the transport parameters for each geometric model is specifically as follows:

[0023] Set the motion parameters through the neutron motion modeling sub - module;

[0024] Set the burnup parameters through the burnup modeling sub - module;

[0025] Set the material parameters through the material activation modeling sub - module;

[0026] Set the dose parameters through the radiation dose modeling sub-module;

[0027] Set the damage parameters through the irradiation damage modeling sub-module.

[0028] Another technical solution of the present invention to solve the above technical problems is as follows: A nuclear simulation analysis method, including:

[0029] The geometric modeling module traverses the high-order surfaces in each geometric model used in the nuclear simulation analysis, performs triangular patch processing on each high-order surface based on the preset patch accuracy, and associates the number of each geometric model with the corresponding patch processing result;

[0030] The physical modeling module sets the neutron source parameters for the neutron source in each geometric model;

[0031] The neutron transport modeling module sets the transport parameters in each geometric model;

[0032] The neutronics multi-physics coupling modeling module is used to perform clipping processing on the original surface in each geometric model through the parametric surface solid clipping method to obtain the mapping relationship between each geometric model and the grids of thermal-hydraulics and structural mechanics;

[0033] The processing module performs nuclear simulation analysis based on the patch processing results of each geometric model, the neutron source parameter setting results of each geometric model, the transport parameter setting results of each geometric model, and each mapping relationship.

[0034] The beneficial effect of the present invention is: The significance of the present invention lies in that an integrated calculation model for comprehensive simulation of different physical processes can be constructed based on a unified framework, the real physical process can be fully considered, and the mutual correlation effects between physical processes in dimensions such as space, energy, and time can be accurately reflected, so as to better serve nuclear simulation analysis.

[0035] Furthermore, it further includes:

[0036] When the boundary surface equation of the geometric model can be expressed by an analytical function, associate the number of the geometric model with the analytical function of the geometric model;

[0037] Or when the boundary surface of the geometric model is a high-order surface, associate the number of the geometric model with the patch processing result of the geometric model.

[0038] Furthermore, the neutron source parameters include:

[0039] The position distribution, energy spectrum, and angular distribution of the neutron source term.

[0040] Furthermore, the process of setting the transport parameters in each geometric model is specifically:

[0041] Set the motion parameters through the neutron motion modeling sub-module;

[0042] Set the burnup parameters through the burnup modeling sub-module;

[0043] Set the material parameters through the material activation modeling sub-module;

[0044] Set the dose parameters through the radiation dose modeling sub-module;

[0045] Set the damage parameters through the irradiation damage modeling sub-module.

[0046] Another technical solution for the present invention to solve the above technical problems is as follows: A storage medium stores instructions, and when a computer reads the instructions, the computer executes the method described in any one of the above.

[0047] The beneficial effect of the present invention is: The significance of the present invention lies in that an integrated calculation model for comprehensive simulation of different physical processes can be constructed based on a unified framework, the real physical process can be fully considered, and the mutual correlation effects between physical processes in dimensions such as space, energy, and time can be accurately reflected, so as to better serve nuclear simulation analysis.

[0048] Another technical solution for the present invention to solve the above technical problems is as follows: An electronic device includes the above storage medium and a processor that executes the instructions in the above storage medium.

[0049] The beneficial effect of the present invention is: The significance of the present invention lies in that an integrated calculation model for comprehensive simulation of different physical processes can be constructed based on a unified framework, the real physical process can be fully considered, and the mutual correlation effects between physical processes in dimensions such as space, energy, and time can be accurately reflected, so as to better serve nuclear simulation analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a structural framework diagram provided for an embodiment of a nuclear simulation analysis system of the present invention;

[0051] Figure 2 It is a flow schematic diagram provided for an embodiment of a nuclear simulation analysis method of the present invention;

[0052] Figure 3 It is an integrated irregular precise modeling system framework diagram provided for an embodiment of a nuclear simulation analysis system of the present invention;

[0053] Figure 4 It is a comparison diagram of an entity model and a patch model provided for an embodiment of a nuclear simulation analysis system of the present invention;

[0054] Figure 5The effect diagram of the decent hybrid model provided by an embodiment of a nuclear simulation analysis system of the present invention;

[0055] Figure 6 The interactive interface diagram of the physical modeling module provided by an embodiment of a nuclear simulation analysis system of the present invention;

[0056] Figure 7 The effect diagram of the visualization of source particle information provided by an embodiment of a nuclear simulation analysis system of the present invention;

[0057] Figure 8 The interactive interface diagram of the neutron transport modeling module provided by an embodiment of a nuclear simulation analysis system of the present invention;

[0058] Figure 9 The schematic diagram of the grid material homogenization process in the neutron transport modeling module provided by an embodiment of a nuclear simulation analysis system of the present invention. Detailed implementation manners

[0059] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0060] As Figure 1 shown, a nuclear simulation analysis system includes: a geometric modeling module 100, a physical modeling module 200, a neutron transport modeling module 300, a neutronics multi-physics coupling modeling module 400, and a processing module 500;

[0061] The geometric modeling module 100 is used to traverse the high-order surfaces in each geometric model used for nuclear simulation analysis, perform triangular patch processing on each high-order surface based on a preset patch accuracy, and associate the number of each geometric model with the corresponding patch processing result;

[0062] The physical modeling module 200 is used to set neutron source parameters for the neutron sources in each geometric model;

[0063] The neutron transport modeling module 300 is used to set transport parameters for each geometric model;

[0064] The neutronics multi-physics coupling modeling module is used to perform trimming processing on the original surfaces in each geometric model through a parametric surface entity trimming method to obtain the mapping relationship between each geometric model and the grids of thermal-hydraulics and structural mechanics;

[0065] The processing module 500 is used to perform nuclear simulation analysis according to the patch processing results of each geometric model, the neutron source parameter setting results of each geometric model, the transport parameter setting results of each geometric model, and each mapping relationship.

[0066] In some possible embodiments, the significance of the present invention lies in that, based on a unified framework, an integrated computational model for comprehensive simulation of different physical processes can be constructed, fully considering the real physical processes, accurately reflecting the interaction among physical processes in dimensions such as space, energy, and time, so as to better serve nuclear simulation analysis, and design optimization or safety evaluation of nuclear energy systems or nuclear technology application systems can be carried out based on the results of nuclear simulation analysis.

[0067] It should be noted that both nuclear energy systems and nuclear technology application systems are existing systems, which can also be understood as systems composed of reactors, etc. Design optimization refers to system parameter optimization based on the results of nuclear simulation analysis, and safety evaluation refers to safety parameter comparison based on the results of nuclear simulation analysis. In the present invention, as Figure 3 shown, the geometric modeling module 100 can achieve accurate expression of irregular geometric bodies based on high-order surface elements and surface-body mixing; the physical modeling module 200 accurately describes the neutron source term of the nuclear simulation analysis calculation model and the nuclide composition of materials based on an interactive interface with parameter visualization; the neutron transport modeling module 300 supports integrated and accurate modeling of physical parameters of neutron motion, nuclide transmutation, and energy deposition; the neutronics multi-physics coupling modeling module 400 supports integrated and accurate modeling of physical parameters of non-regular coupling of neutron transport with thermal-hydraulics, structural mechanics, chemistry, biology, and electromagnetics.

[0068] The geometric modeling module 100, the feature of high-order surface elements lies in judging whether the equation of the boundary surface of the geometric body (geometric model) can be expressed by an analytical function. Based on this, it can be determined whether the geometric body is an analytical surface. It should be noted that the geometric model is not limited to the reactor model required for nuclear simulation analysis, but may also include other required models.

[0069] For non-analytical surfaces, for high-order surfaces in a geometric body (a geometric model file stored in a standard 3D CAD format, containing several 3D geometric bodies, and the geometric bodies are described using the boundary representation method BREP (Boundary REPresentation)), traverse the geometric bodies in the 3D CAD model to obtain a list of the boundary surfaces of each geometric body, and then determine whether it is a high-order surface (including B-spline surfaces, Swept surfaces, etc.) by judging the type of each boundary surface. Perform tessellation processing according to the set precision, and then perform triangular tessellation on the high-order surface according to the requirements of the tessellation precision (that is, the maximum distance between the tessellated geometric surface (the tessellated geometric surface refers to the basic unit of the tessellation, that is, a plane or surface with a finite area, such as a common triangular patch, and the boundary surface of the geometric body is described by a set of basic units (called "patches") with a finite area of planes or surfaces, etc.). In the tessellated geometry, instead of using a complete boundary surface (surface), many patches are used to approximate the boundary surface of the geometric body. Theoretically, as long as the number of patches is large enough, a high-precision tessellated geometric model can be created)) and the original exact geometric surface (the original exact geometric surface refers to the boundary surface of the geometric body), and record the triangular patch information corresponding to the original exact geometric surface (including the index number, vertex coordinates, and topological structure of each triangular patch); it should be noted that the triangular patch information is used for subsequent particle transport simulation in the transport calculation process. For geometric bodies described by the patch model, the above information will be used for particle transport simulation, that is, to determine the geometric body to which the current position of the particle belongs and the distance from the particle to the boundary of the geometric body; for geometric bodies described by the composite solid geometry model, the analytical equation of the boundary surface is directly used for particle transport simulation.

[0070] For analytical surfaces, the feature of solid-surface mixing (which means that the geometric bodies in the transport calculation model are defined in two different ways. For geometric bodies containing only analytical surfaces, the composite solid geometry model is used for construction (solid → composite solid model), and for complex geometric bodies containing high-order surfaces, the patch model is used for construction (surface → patch model)) is that for geometric bodies containing only analytical surfaces, the composite solid geometry model (the composite solid geometry model refers to a description method (already disclosed) of geometric bodies, which uses half-spaces formed by regular analytical surfaces as basic elements and combines these basic elements through Boolean operations (Boolean union, Boolean intersection, Boolean subtraction) to describe complex 3D geometric bodies; the input is the geometric body, and the output is the analytical equation of each boundary surface in the geometric body and the relationship between each boundary surface (described by the rules of Boolean operations))

[0071] Through this description method, by means of the equations of the boundary surfaces and the mutual relationships between the boundary surfaces, it is possible to determine the positional relationship between the particles and the geometric body in the transport calculation and calculate the distance from the particles to the boundary surface of the geometric body, which is constructed as a support function for the transport calculation. For complex geometric bodies containing high-order surfaces (by traversing the geometric bodies in the 3D CAD model, obtaining a list of the boundary surfaces of each geometric body, and then by judging the type of each boundary surface, it is known whether it is a high-order surface (including B-spline surfaces, Swept surfaces, etc.), because analytic surfaces all have corresponding surface types (such as planes, spherical surfaces, cylindrical surfaces, conical surfaces, etc.)), a patch model is used to construct (the patch model is also one of the existing models at present, with the geometric body as the input and the triangular patch information (including the index numbers of each triangular patch, vertex coordinates, and topological structure) as the output; through the information of the triangular patches, it is possible to determine the positional relationship between the particles and the geometric body in the transport calculation and calculate the distance from the particles to the boundary surface of the geometric body, which is constructed as a support function for the transport calculation). A grid model is constructed in the coupled calculation region of other physical processes such as thermal-hydraulics and structural mechanics, and a voxel model is constructed for the staff in the entire nuclear energy system to establish a geometric model for neutron transport and multi-physics coupling of neutronics (the grid model refers to expressing the geometric body in the model through the collection of some basic units such as cuboids, tetrahedrons, and hexahedrons (referred to as "grids"); the voxel model is based on voxels as basic units and is stacked according to the human anatomical structure. Each voxel represents a specific substance and defines the density and elemental composition of the substance. The voxels with the same substance composition constitute a specific organ or tissue).

[0072] The physical modeling module 200 is characterized in that, based on the visual geometric model created by the geometric modeling module 100, a parameter-visualized interactive interface is used to set the position distribution, energy spectrum, and angular distribution of the neutron source term, and the source particles are visually displayed in the geometric model to intuitively judge the correctness of the source term parameter settings; based on professional nuclear databases (including transport nuclear databases, transmutation nuclear reaction databases, decay databases, fission yield databases, and radiation damage nuclear databases), and according to the geometric boundaries created in the geometric modeling module 100, the material density, temperature, and nuclide composition are set for each geometric body (for each geometric body, the temperature and density values of the geometric body can be directly set on the interface. At the same time, based on the nuclear database, the types and contents (mass percentage or nucleon percentage) of each nuclide contained in the material of the geometric body can be set on the interface). The processing result of the physical modeling module is to complete the settings of the source term, material density, temperature, and nuclide composition and other information required for the transport calculation, and generate the parameter information required for the calculation model file.

[0073] Neutron transport modeling module 300, characterized in that neutron transport studies the motion of neutrons and nuclear reaction processes in a medium, including neutron motion, nuclide transmutation, and energy deposition processes. Among them, neutron motion studies the motion law of neutrons in the medium, nuclide transmutation includes processes such as burnup, nuclear waste transmutation, nuclear fuel breeding, and material activation, and energy deposition is the main factor causing human radiation dose hazards and irradiation damage to devices; the neutron motion modeling sub-module supports the setting of neutron / photon transport physical models, variance reduction techniques, and core physics / shielding calculation parameter statistics; the burnup modeling sub-module supports the setting of burnup depth, power density, and boron concentration in the burnup zone and each burnup step; the material activation modeling sub-module supports the setting of the activation zone, irradiation / cooling scheme, and activation characteristic quantities; the radiation dose modeling sub-module supports the setting of the dose counting zone and flux-dose conversion factor; the irradiation damage modeling sub-module supports the parameter statistics setting of DPA, gas production rate, Kerma, recoil spectrum, and total damage energy; at the same time, the sub-modules are coupled with each other to establish the mutual correlation of physical parameters such as neutron flux spectrum, reaction rate, and nucleon density between different processes, transfer data within the system, and realize the integrated and accurate modeling of neutron transport (using the nucleon density distribution, neutron transport calculation can obtain the neutron flux spectrum; multiplying the neutron flux spectrum by the reaction cross-section of the corresponding nuclide can obtain the reaction rate; then, using the reaction rate for burnup calculation can obtain the distribution of nucleon density. Through the above relationships, the correlation between physical parameters such as nucleon density, neutron flux spectrum, and reaction rate can be established).

[0074] Neutronics multi-physics coupling modeling module 400, characterized in that by means of the geometry modeling module 100, using the parametric surface solid clipping method (that is, converting the combined entity geometry model used in the transport calculation into a Boolean operation of parametric surfaces. Then, converting the unstructured grids used in thermal-hydraulics and structural mechanics calculations into Boolean operations of parametric surfaces. Obviously, each parametric surface of the grid represents a half-space. Finally, using all the parametric surfaces corresponding to the unstructured grid to shear the parametric surface corresponding to the combined entity geometry, the volume of the new geometry obtained is the intersection volume of the geometry in the transport calculation and the unstructured grid), converting the grid described by points and faces into a Boolean operation of parametric surfaces (based on the point and face descriptions in the unstructured grid, directly generating multiple planes, and then establishing the Boolean intersection operation relationship between multiple planes), and then using all the parametric surfaces of the grid to shear the combined entity geometry to obtain the intersection volume of the combined entity geometry and the grid, realizing the automatic and accurate geometric mapping between the combined entity geometry and the unstructured grid. The following is a specific explanatory description of each module in combination with the attached drawings.

[0075] 1. Geometry modeling module 100

[0076] (1) High-order surface patches

[0077] Traditional manual regularized approximation modeling methods usually use simplified modeling to approximately represent irregular boundaries when dealing with complex-shaped irregular geometric bodies. This results in low model accuracy, as well as a time-consuming, unintuitive, and error-prone modeling process. Patch modeling can describe the boundary surfaces of entities through the collection of some basic units with finite areas, such as planes or curved surfaces (referred to as "patches"), and then express the entire computational space. In patch geometry, instead of using a complete curved surface, many patches are used to approximate the surface of the entity. Theoretically, as long as the number of patches is large enough, a high-precision computational model can be created.

[0078] Common patch geometries are enclosed by triangular patches. The triangular patches are adjacent to each other in pairs by edges, and each edge must have adjacent patches to ensure its sealing. The basic process of patch modeling is to first traverse each face in the geometric body, then perform triangular patchification on each face according to the patchification accuracy requirements, and record the set of triangular patch information corresponding to the original face (including the index numbers, vertex coordinates, topological structures, etc. of each triangular patch). Process all geometric bodies in the CAD model according to the above method, and finally complete the creation of the patch model.

[0079] After the CAD model is patchified, the maximum distance d between the patch geometric surface and the original precise geometric surface characterizes the accuracy of the patch model. Figure 4 Figure 8 is a comparison diagram of the solid model and the patch model. It can be seen from the figure that the number of patches increases rapidly as the maximum distance decreases. To accurately describe high-order curved surfaces, d usually needs to be set to a small value, resulting in a significant increase in the number of patches, thus reducing the computational efficiency. Therefore, it is necessary to balance the contradiction between the accuracy of patch modeling and the computational efficiency in order to achieve high-precision and efficient neutronics calculations based on the patch model.

[0080] (2) Solid-surface hybrid

[0081] CSG models can handle a variety of common complex curved surfaces, and the established computational models are concisely expressed, making it convenient and fast to track the trajectories of particles in geometric bodies; however, they cannot describe high-order complex curved surfaces and require a large amount of preprocessing. Patch or mesh models can realistically approximate high-order complex curved surfaces through a large number of patches or meshes without preprocessing the model, saving the time for model generation; but due to the use of a large number of patches or meshes, it will not only have a certain impact on the computational accuracy of the model, but also reduce the computational efficiency. In addition, mesh models have been widely used in the computational analysis of various physical processes such as thermal-hydraulics and structural mechanics, while voxel models are mainly used to analyze the impact of the radiation environment on the human body.

[0082] Therefore, establishing an adaptive decent hybrid model based on model characteristics and giving full play to the respective advantages of various expression methods such as CSG models, faceted models, mesh models, and voxel models is of great significance for improving the accuracy and efficiency of comprehensive neutronics simulations. For geometric bodies containing only analytical surfaces, CSG models are used for construction; for geometric bodies containing high-order complex surfaces, faceted models are used for construction; mesh models are constructed in the coupling calculation regions of other physical processes such as thermal-hydraulics and structural mechanics; and voxel models are constructed for the staff in the entire nuclear energy system. In this way, a full-space neutronics calculation model can be established to perform computational analysis of neutron transport and neutronics multi-physics coupling in advanced nuclear energy systems.

[0083] Figure 5 An adaptive decent hybrid model of the Japanese stellarator-type fusion system (Force Free Helical Reactor, FFHR) is presented. By judging the surface types of the entities in the CAD model, only corresponding faceted descriptions are generated for high-order surfaces, while other surfaces still use CSG descriptions, thus significantly reducing the number of facets and improving the calculation efficiency.

[0084] 2. Physical Modeling Module 200

[0085] Based on an interactive interface with parameter visualization (as shown in Figure 6 ), the neutron source term and the nuclide composition of materials in the nuclear simulation analysis calculation model are accurately described. For the visualization of source particle information, first, by reading the source parameters in the physical modeling module 200, the type, position, and shape of the source are obtained. Then, based on the HOOPS visualization framework, the position, shape, energy, direction, and distribution of the source are visually presented in three dimensions.

[0086] Taking a cylindrical surface source as an example, after obtaining the source parameters from the physical modeling module 200, a new source geometry rendering segment is created in the current view interface of the HOOPS framework to construct the geometric model of the source. Then, the particle information of the source (including energy, direction, and position) is obtained from the source sampling program. The energy distribution of the particles is calibrated with a gradient color bar, the direction of the particles is described by the short-time movement trajectories of the particles, and the spatial distribution of the source particles is described by the actually sampled particle positions. Particle visualization segments are created under the segments of the source geometry, and models of particles are created in batches. The coordinates of the particles at different times in the current movement direction are calculated. Based on these coordinates, the view is repeatedly updated at an appropriate frame rate to achieve three-dimensional intuitive dynamic visualization of the cuboid source, as shown in Figure 7 ), enabling users to very conveniently check the correctness of the relevant physical parameter settings.

[0087] 3. Neutron Transport Modeling Module 300

[0088] Based on the parameter visualization interactive interface, parameter modeling is carried out for neutron motion, nuclide transmutation (including processes such as burnup, nuclear waste transmutation, nuclear fuel breeding, material activation, etc.), and energy deposition (the main factors causing human radiation dose hazards and device irradiation damage). The modeling interfaces of each sub-module are as Figure 8 shown. Among them, the neutron motion modeling sub-module supports the setting of neutron / photon transport physical models, variance reduction techniques, and core physics / shielding calculation parameter statistics; the burnup modeling sub-module supports the setting of burnup depth, power density, and boron concentration in the burnup zone and each burnup step; the material activation modeling sub-module supports the setting of the activation zone, irradiation / cooling schemes, and activation characteristic quantities; the radiation dose sub-module supports the setting of the dose counting area and the flux-dose conversion factor; the irradiation damage modeling sub-module supports the parameter statistics setting of DPA, gas production rate, Kerma, recoil spectrum, and total damage energy.

[0089] At the same time, each sub-module is mutually coupled to establish the mutual correlation of physical parameters such as neutron flux spectrum, reaction rate, and nucleon density between different processes, transfer data within the system, and achieve an integrated and accurate modeling of neutron transport. Taking activation modeling as an example, when the activation zone grid spans multiple material regions, the bounding box data is quickly generated based on the CAD model, and the grids intersecting with the bounding box are determined, so as to quickly judge which fuel assemblies the grid intersects with. Finally, the volume fraction of different materials in the grid is calculated by point projection within the grid, as Figure 9 shown. The point projection position (x, y, z) is determined by random sampling in the following formula.

[0090] x = ξ1(x max -x min ) + x min

[0091] y = ξ2(y max -y min ) + y min

[0092] z = ξ3(z max -z min ) + z min

[0093] where x max , y max , z max are the maximum values of the grid in each coordinate system respectively, x min , y min , z min are the minimum values, and ξ1, ξ2, and ξ3 are different random numbers. After point projection, the average material density of the grid is obtained by the following formula,

[0094]

[0095] where ρ i is the atomic density of the i-th material, and n i is the number of sampling points corresponding to this material.

[0096] 4. Neutronics multi-physics coupling modeling module 400

[0097] The specific method for trimming parametric surface entities is as follows: Based on a unified framework, an integrated and accurate modeling of the coupling of neutronics with thermal-hydraulics, structural mechanics, chemistry, biology, and electromagnetics is achieved. Among them, the geometric mapping method based on entity trimming mainly includes the following steps:

[0098] Use the axial bounding box to quickly screen out the unstructured grids that may intersect with the target geometric lattice cell;

[0099] Convert the geometric lattice cell into a geometric entity represented by a parametric surface, convert each face of the unstructured grid into a half-plane space, and sequentially use these half-plane spaces to trim the geometric entity based on Boolean operations;

[0100] Calculate the volume of the trimmed geometric entity and use it as the intersection volume. If this volume is greater than zero, it indicates that the geometric lattice cell and the unstructured grid intersect; otherwise, it indicates that the two do not intersect;

[0101] Repeat the above process to find all the unstructured grids that intersect with this geometric lattice cell, and establish a geometric mapping relationship with the intersection volume as the weight.

[0102] Preferably, in any of the above embodiments, the geometric modeling module 100 is further configured to:

[0103] When the boundary surface equation of the geometric model can be expressed by an analytical function, associate the number of the geometric model with the analytical function of the geometric model;

[0104] Or when the boundary surface of the geometric model is a high-order surface, associate the number of the geometric model with the result of the faceting process of the geometric model.

[0105] Preferably, in any of the above embodiments, the neutron source parameters include:

[0106] The position distribution, energy spectrum, and angular distribution of the neutron source term.

[0107] Preferably, in any of the above embodiments, the process of setting the transport parameters in each geometric model is specifically as follows:

[0108] Set the motion parameters through the neutron motion modeling sub-module;

[0109] Set the burnup parameters through the burnup modeling sub-module;

[0110] Set the material parameters through the material activation modeling sub-module;

[0111] Set the dose parameters through the radiation dose modeling sub-module;

[0112] Set the damage parameters through the irradiation damage modeling sub-module.

[0113] As Figure 2 shown, a nuclear simulation analysis method includes:

[0114] The geometric modeling module 100 traverses the high-order surfaces in each geometric model used in the nuclear simulation analysis, performs triangular meshing on each high-order surface based on the preset meshing accuracy, and associates the number of each geometric model with the corresponding meshing result;

[0115] The physical modeling module 200 sets the neutron source parameters for the neutron source in each geometric model;

[0116] The neutron transport modeling module 300 sets the transport parameters in each geometric model;

[0117] The neutronics multi-physics coupling modeling module is used to cut the original surface in each geometric model by the parametric surface solid cutting method to obtain the mapping relationship between each geometric model and the grids of thermal-hydraulics and structural mechanics;

[0118] The processing module 500 performs nuclear simulation analysis according to the meshing result of each geometric model, the setting result of the neutron source parameters of each geometric model, the setting result of the transport parameters of each geometric model, and each mapping relationship, and performs design optimization or safety evaluation processing on the nuclear energy system or nuclear technology application system based on the nuclear simulation analysis result.

[0119] In some possible implementation manners, the significance of the present invention lies in that an integrated calculation model for comprehensive simulation of different physical processes can be constructed based on a unified framework, the real physical process can be completely considered, and the mutual correlation effects between various physical processes in dimensions such as space, energy, and time can be accurately reflected, so as to better serve nuclear simulation analysis.

[0120] Preferably, in any of the above embodiments, it further includes:

[0121] When the boundary surface equation of the geometric model can be expressed by an analytical function, associate the number of the geometric model with the analytical function of the geometric model;

[0122] Or when the boundary surface of the geometric model is a high-order surface, associate the number of the geometric model with the meshing result of the geometric model.

[0123] Preferably, in any of the above embodiments, the neutron source parameters include:

[0124] The position distribution, energy spectrum, and angular distribution of the neutron source term.

[0125] Preferably, in any of the above embodiments, the process of setting the transport parameters in each geometric model is specifically as follows:

[0126] Set the motion parameters through the neutron motion modeling sub-module;

[0127] Set the burnup parameters through the burnup modeling sub-module;

[0128] Set the material parameters through the material activation modeling sub-module;

[0129] Set the dose parameters through the radiation dose modeling sub-module;

[0130] Set the damage parameters through the irradiation damage modeling sub-module.

[0131] Another technical solution for the present invention to solve the above technical problems is as follows: A storage medium stores instructions, and when a computer reads the instructions, it causes the computer to execute the method according to any one of the above.

[0132] In some possible implementation manners, the significance of the present invention lies in that an integrated calculation model for comprehensive simulation of different physical processes can be constructed based on a unified framework, the real physical process can be fully considered, and the mutual correlation effects between various physical processes in dimensions such as space, energy, and time can be accurately reflected, so as to better serve nuclear simulation analysis.

[0133] Another technical solution for the present invention to solve the above technical problems is as follows: An electronic device includes the above storage medium and a processor that executes the instructions in the above storage medium.

[0134] In some possible implementation manners, the significance of the present invention lies in that an integrated calculation model for comprehensive simulation of different physical processes can be constructed based on a unified framework, the real physical process can be fully considered, and the mutual correlation effects between various physical processes in dimensions such as space, energy, and time can be accurately reflected, so as to better serve nuclear simulation analysis.

[0135] Readers should understand that in the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", 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 the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0136] In several embodiments provided by this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the method embodiments described above are merely illustrative. For example, the division of steps is only a logical function division. In actual implementation, there can be other division methods. For example, multiple steps can be combined or integrated into another step, or some features can be ignored or not executed.

[0137] If the above method is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. And the aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0138] The above are only the specific implementation manners of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A nuclear simulation analysis system, characterized in that, Including: A geometric modeling module, a physical modeling module, a neutron transport modeling module, a neutronics multi-physics coupling modeling module, and a processing module; The geometric modeling module is used to traverse the high-order surfaces in each geometric model used for nuclear simulation analysis, perform triangular patch processing on each high-order surface based on a preset patch accuracy, and associate the number of each geometric model with the corresponding patch processing result; The physical modeling module is used to set neutron source parameters for the neutron source in each geometric model; The neutron transport modeling module is used to set transport parameters in each geometric model; The neutronics multi-physics coupling modeling module is used to perform clipping processing on the original surface in each geometric model by a parametric surface solid clipping method to obtain the mapping relationship between the grids of each geometric model and thermal-hydraulics and structural mechanics; The processing module is used to perform nuclear simulation analysis based on the patch processing result of each geometric model, the neutron source parameter setting result of each geometric model, the transport parameter setting result of each geometric model, and each mapping relationship, and perform design optimization or safety evaluation processing on the nuclear energy system or nuclear technology application system based on the nuclear simulation analysis result.

2. The nuclear simulation analysis system according to claim 1, characterized in that, The geometric modeling module is further used for: When the boundary surface equation of the geometric model can be expressed by an analytical function, associating the number of the geometric model with the analytical function of the geometric model; Or when the boundary surface of the geometric model is a high-order surface, associating the number of the geometric model with the patch processing result of the geometric model.

3. A nuclear simulation analysis system according to claim 1, characterized in that, The neutron source parameters include: The position distribution, energy spectrum, and angular distribution of the neutron source term.

4. A nuclear simulation analysis system according to claim 1, characterized in that, The process of setting the transport parameters in each geometric model is specifically as follows: Setting the motion parameters through the neutron motion modeling sub-module; Setting the burnup parameters through the burnup modeling sub-module; Setting the material parameters through the material activation modeling sub-module; Setting the dose parameters through the radiation dose modeling sub-module; Setting the damage parameters through the irradiation damage modeling sub-module.

5. A nuclear simulation analysis method, characterized in that, Including: The geometric modeling module traverses the high-order surfaces in each geometric model used for nuclear simulation analysis, performs triangular patch processing on each high-order surface based on a preset patch accuracy, and associates the number of each geometric model with the corresponding patch processing result; The physical modeling module sets neutron source parameters for the neutron source in each geometric model; The neutron transport modeling module sets transport parameters in each geometric model; The neutronics multi-physics coupling modeling module is used to perform clipping processing on the original surface in each geometric model by a parametric surface solid clipping method to obtain the mapping relationship between the grids of each geometric model and thermal-hydraulics and structural mechanics; The processing module performs nuclear simulation analysis based on the patch processing result of each geometric model, the neutron source parameter setting result of each geometric model, the transport parameter setting result of each geometric model, and each mapping relationship, and performs design optimization or safety evaluation processing on the nuclear energy system or nuclear technology application system based on the nuclear simulation analysis result.

6. The nuclear simulation analysis method according to claim 5, wherein Also including: When the boundary surface equation of the geometric model can be expressed by an analytical function, associate the number of the geometric model with the analytical function of the geometric model; Or when the boundary surface of the geometric model is a high-order surface, associate the number of the geometric model with the result of the tessellation processing of the geometric model.

7. A nuclear simulation analysis method according to claim 5, characterized in that, The neutron source parameters include: The position distribution, energy spectrum, and angular distribution of the neutron source term.

8. A nuclear simulation analysis method according to claim 5, characterized in that, The process of setting the transport parameters in each geometric model is specifically as follows: Set the motion parameters through the neutron motion modeling sub-module; Set the burnup parameters through the burnup modeling sub-module; Set the material parameters through the material activation modeling sub-module; Set the dose parameters through the radiation dose modeling sub-module; Set the damage parameters through the irradiation damage modeling sub-module.

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