1. A method for analyzing and calculating the performance of a reactor fuel, comprising:

generating a time sequence of the fuel rod to be analyzed, and axially dividing the geometric structure of the fuel rod into different axial segments;

carrying out global calculation on the fuel rod to be analyzed in each time step, and carrying out thermal coupling analysis;

local calculation is carried out on different axial subsections of the fuel rod after the thermodynamic coupling analysis, and multi-physical field analysis is realized; the multi-physics include fuel reconstitution, component redistribution, fission gas release and swelling, cladding corrosion, and core chemical interactions.

2. The method of claim 1, wherein the method of generating a time series of fuel rods to be analyzed comprises: and setting time steps of different behavior models of the fuel rods, and setting a time sequence according to the irradiation history of the reactor.

3. The method of claim 1, further comprising discretizing the computational domain radially of the fuel rod geometry into nested node rings in synchronization with the axially slicing of the fuel rod geometry into different axial segments to generate a computational grid of the fuel rod simulation, and discretizing the global and local computations by finite volume methods.

4. The method of claim 1, wherein performing a global calculation for the fuel rod under analysis at each time step comprises:

calculating the pre-estimated temperature distribution in the fuel rod under the current working condition, wherein the pre-estimated temperature distribution comprises core cladding temperature distribution, clearance heat transfer and coolant axial temperature distribution;

according to the pre-estimated temperature distribution inside the fuel rod, calculating to obtain the initial mechanical analysis under the current pre-estimated temperature, wherein the initial mechanical analysis comprises stress distribution of pellets and cladding, node elastoplasticity, creep, swelling strain, radial displacement and axial extension;

judging whether the core cladding contact is converged according to the stress distribution of the core pellets and the cladding; if the pressure is converged, the pressure of the air cavity in the current state is calculated according to the estimated temperature distribution, whether the pressure of the air cavity is converged or not is judged, and local calculation is carried out if the pressure is converged.

5. The method of claim 4, wherein the criterion for determining whether the core contact converges is: adjusting the contact pressure load until whether the invasion depth of the core package clearance meets a first preset value or not, and converging if the invasion depth meets the first preset value;

the criterion for judging whether the pressure of the air cavity is converged is as follows: whether the pressure of the air cavity meets a second preset value or not, and if so, convergence is achieved.

6. The method of claim 1, wherein locally computing different axial segments of the fuel rod after the thermal coupling analysis comprises:

and (3) fuel reconfiguration: calculating pore migration, central opening and grain growth caused by high temperature and large temperature gradient;

redistribution of components: solving the change of O/M ratio and stoichiometric state of the fuel caused by the migration and transportation of oxygen and actinides in the fuel;

fission gas release and swelling: calculating and analyzing the generation, nucleation, growth, polymerization, re-dissolution and fuel swelling phenomena caused by the interaction process with grain boundaries and defects of insoluble and volatile gases in the fuel;

cladding corrosion and core chemical interaction: and (4) calculating and analyzing corrosion of the outer wall surface of the cladding caused by liquid metal coolant scouring and chemical reaction and the corrosion process of the inner wall surface FCCI.

7. The method of claim 1, wherein prior to the step of generating the time series of fuel rods to be analyzed, the method further comprises:

the active segment, the air cavity and the corresponding cladding part of the fast reactor fuel rod are used as analysis and simulation objects, the geometric structure, the material physical property and the reactor operation condition of the fast reactor fuel rod are input, and the actual operation condition and the irradiation history of the fuel rod are determined.

8. A reactor fuel performance analysis computing system, comprising: the system comprises a space-time discrete module, a global calculation module and a local calculation module;

the space-time discrete module generates a time sequence of the fuel rod to be analyzed and divides the geometric structure of the fuel rod into different axial segments in the axial direction;

the global calculation module is used for carrying out global calculation on the fuel rod to be analyzed in each time step and carrying out thermal coupling analysis;

the local calculation module is used for carrying out local calculation on different axial subsections of the fuel rod after the thermal coupling analysis so as to realize multi-physical field analysis; the multi-physics include fuel reconstitution, component redistribution, fission gas release and swelling, cladding corrosion, and core chemical interactions.

9. A computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by a computing device, cause the computing device to perform any of the methods of claims 1-7.

10. A computing device, comprising: one or more processors, memory, and one or more programs stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for performing any of the methods of claims 1-7.

Background

Under the complex service environments of high temperature, high neutron fluence, severe nuclear reaction, chemical reaction and the like in a reactor, the interior of a fuel element evolves from a microscopic atomic scale to a macroscopic structure scale and simultaneously experiences the neutron chemistry feedback from a microsecond level to the service life of decades. These special service conditions, which span multiple physical fields, large spatio-temporal scales, lead to a very complex evolution of the behavior of the fuel elements. The precise description of the problem involves many disciplines such as chemistry, physics, metallurgy, mechanics and materials, and its inherent non-linear characteristics make a purely analytical solution impossible.

With the widespread commercialization of the second-generation and third-generation nuclear energy systems mainly based on the light water reactor, a great deal of LWR fuel performance simulation and experimental research is carried out by different countries and international organizations, so that the performance analysis method for the light water reactor fuel element is relatively mature. Compared with a water reactor, the neutron energy spectrum in the lead-based fast reactor is harder, the power density and the burnup depth are larger, so that the phenomena of obvious chemical correlation effects such as liquid lead-bismuth corrosion and the like of fuel elements, fission gas release and the like exist, the time characteristics of the phenomena and the interaction among the phenomena are very complex, and great troubles are brought to analog analysis and coupling calculation. In addition, because of the scarcity of in-stack experimental data of the fast reactor system and the insufficient theoretical research, the development amount of fuel element analysis programs for the fast reactor is small, and no water reactor is mature.

The performance analysis methods designed by taking water reactor fuel elements as research objects at present can be divided into two main categories: in the method, a fuel thermodynamic analysis and other behavior models execute the same subarea calculation process, all parameters are transmitted in a time step mode under the condition that the calculation is not converged globally, so that not only is the parameter transmission lagged, but also the program calculation distortion and convergence difficulty are caused; the second method is to carry out three-dimensional modeling on local fuel sections and develop a multi-scale fuel analysis program by means of a three-dimensional computing platform, and the method can realize three-dimensional fine computation of local areas of the fuel, but the computation amount is too large, and the analysis and computation of the whole rod cannot be carried out on the premise of limited computing resources.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a calculation method, a system, a storage medium, and a device for analyzing fuel performance of a lead-based fast reactor oxide reactor, which solve the problems of delay of parameter transmission and distortion of program calculation in a past program in a time step.

In order to achieve the above object, in a first aspect, the present invention adopts the following technical solutions: a method of reactor fuel performance analysis calculation, comprising: generating a time sequence of the fuel rod to be analyzed, and axially dividing the geometric structure of the fuel rod into different axial segments; carrying out global calculation on the fuel rod to be analyzed in each time step, and carrying out thermal coupling analysis; local calculation is carried out on different axial subsections of the fuel rod after the thermodynamic coupling analysis, and multi-physical field analysis is realized; the multi-physics include fuel reconstitution, component redistribution, fission gas release and swelling, cladding corrosion, and core chemical interactions.

Further, the method for generating the time series of the fuel rods to be analyzed comprises the following steps: and setting time steps of different behavior models of the fuel rods, and setting a time sequence according to the irradiation history of the reactor.

Further, the calculation area is dispersed into node rings which are mutually nested in the radial direction of the geometrical structure of the fuel rod to generate a calculation grid of the fuel rod simulation, and the global calculation and the local calculation are subjected to discrete solution through a finite volume method.

Further, the performing global calculation on the fuel rod to be analyzed in each time step includes:

calculating the pre-estimated temperature distribution in the fuel rod under the current working condition, wherein the pre-estimated temperature distribution comprises core cladding temperature distribution, clearance heat transfer and coolant axial temperature distribution;

according to the pre-estimated temperature distribution inside the fuel rod, calculating to obtain the initial mechanical analysis under the current pre-estimated temperature, wherein the initial mechanical analysis comprises stress distribution of pellets and cladding, node elastoplasticity, creep, swelling strain, radial displacement and axial extension;

judging whether the core cladding contact is converged according to the stress distribution of the core pellets and the cladding; if the pressure is converged, the pressure of the air cavity in the current state is calculated according to the estimated temperature distribution, whether the pressure of the air cavity is converged or not is judged, and local calculation is carried out if the pressure is converged.

Further, the criterion for judging whether the core package contact converges is as follows: adjusting the contact pressure load until whether the invasion depth of the core package clearance meets a first preset value or not, and converging if the invasion depth meets the first preset value;

the criterion for judging whether the pressure of the air cavity is converged is as follows: whether the pressure of the air cavity meets a second preset value or not, and if so, convergence is achieved.

Further, the locally calculating the different axial segments of the fuel rod after the thermal coupling analysis includes:

and (3) fuel reconfiguration: calculating pore migration, central opening and grain growth caused by high temperature and large temperature gradient;

redistribution of components: solving the change of O/M ratio and stoichiometric state of the fuel caused by the migration and transportation of oxygen and actinides in the fuel;

fission gas release and swelling: calculating and analyzing the generation, nucleation, growth, polymerization, re-dissolution and fuel swelling phenomena caused by the interaction process with grain boundaries and defects of insoluble and volatile gases in the fuel;

cladding corrosion and core chemical interaction: and (4) calculating and analyzing corrosion of the outer wall surface of the cladding caused by liquid metal coolant scouring and chemical reaction and the corrosion process of the inner wall surface FCCI.

Further, before the step of generating a time series of fuel rods to be analyzed, the method further comprises:

the active segment, the air cavity and the corresponding cladding part of the fast reactor fuel rod are used as analysis and simulation objects, the geometric structure, the material physical property and the reactor operation condition of the fast reactor fuel rod are input, and the actual operation condition and the irradiation history of the fuel rod are determined.

In a second aspect, the invention adopts the following technical scheme: a reactor fuel performance analysis computing system, comprising: the system comprises a space-time discrete module, a global calculation module and a local calculation module;

the space-time discrete module generates a time sequence of the fuel rod to be analyzed and divides the geometric structure of the fuel rod into different axial segments in the axial direction;

the global calculation module is used for carrying out global calculation on the fuel rod to be analyzed in each time step and carrying out thermal coupling analysis;

the local calculation module is used for carrying out local calculation on different axial subsections of the fuel rod after the thermal coupling analysis so as to realize multi-physical field analysis; the multi-physics include fuel reconstitution, component redistribution, fission gas release and swelling, cladding corrosion, and core chemical interactions.

In a third aspect, the invention adopts the following technical scheme: a computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by a computing device, cause the computing device to perform any of the methods as described above.

In a fourth aspect, the invention adopts the following technical scheme: a computing device, comprising: one or more processors, memory, and one or more programs stored in the memory and configured for execution by the one or more processors, the one or more programs including instructions for performing any of the methods described above.

Due to the adoption of the technical scheme, the invention has the following advantages:

1. the fuel rod analysis method provided by the invention has the advantages that the 1.5-dimensional axial stacking assumption is adopted to disperse the fuel rod analysis area into the node rings with axial segmentation and radial mutual nesting under the cylindrical coordinate system, the global thermal analysis and the local behavior simulation of the fuel rod are coupled through a two-step analysis method, and the problems of parameter transmission lag and program calculation distortion of the conventional program under the step of time span are solved.

2. Compared with a local coupling method, the fuel global thermal analysis and local behavior simulation are coupled by adopting a two-step analysis method, the global coupling thermal analysis is taken as a main part, the fast response process of the fuel rod under the conditions of evolution in the reactor irradiation process and power transient can be simulated more accurately, and the calculation precision and accuracy are higher.

3. The invention uses computer numerical calculation to simulate the service performance of the fuel element, establishes the algorithm logic of fuel behavior models with different time scales, performs global thermal analysis on the fuel rod, couples various behaviors of the fuel pellet and the cladding in the stack, and tracks the evolution of important characteristics along with the irradiation time, thereby predicting the performance of the fuel rod under various operating conditions. The method provides reference for the design of the lead-based fast reactor fuel and provides basis for fuel preparation, in-reactor irradiation and out-of-reactor experimental research.

Drawings

FIG. 1 is a general flow chart of a fuel property analysis calculation method according to an embodiment of the present invention;

FIG. 2 is a detailed flow chart of a fuel property analysis calculation method according to an embodiment of the present invention;

FIG. 3 is a calculated fuel rod radial temperature profile in accordance with an embodiment of the present invention;

FIG. 4 is a calculated fuel rod internal principal stress distribution map in accordance with an embodiment of the present invention;

FIG. 5 is a graph illustrating the calculated boundary displacement of each control body within a fuel pellet;

FIG. 6 is a calculated internal radial porosity profile of a fuel pellet in accordance with an embodiment of the present invention;

FIG. 7 is a calculated radial O/M ratio profile inside a fuel pellet in accordance with an embodiment of the present invention;

FIG. 8 is a schematic diagram of a fuel element performance analysis computing system in accordance with an embodiment of the present invention;

FIG. 9 is a diagram of a computing device in accordance with an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention, are within the scope of the invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The method comprises the steps of dispersing the geometrical structure of the fuel rod into different calculation control bodies according to input initial conditions, segmenting a time control sequence according to input irradiation history, performing full-rod thermal coupling analysis under the current time step by establishing core-cladding contact iteration and gas cavity pressure iteration, and performing local fuel reconstruction process evolution, component migration, fission gas release, cladding corrosion, core-cladding chemical interaction and other calculations on each axial segment of the fuel. The invention couples the global thermodynamic analysis and the local behavior simulation of the fuel rod through two-step analysis, and solves the problems of the delay of thermodynamic parameter transmission and the distortion of the global calculation of the program under the step of time span of the conventional program. Compared with the 1.5-dimensional axial local coupling method, the method has higher global calculation precision and can better reflect and process the fast response problem under the conditions of evolution and frequent power change of the fuel rod in the in-reactor service process.

In addition, aiming at the lead-based fast reactor fuel element, a serial coupling mode and algorithm logic of behavioral models of fast reactor fuel thermal analysis and fuel reconstruction, component redistribution, fission gas release, cladding corrosion, core chemical interaction and the like are established, and a solution is provided for fast reactor fuel performance analysis and simulation calculation.

In an embodiment of the present invention, as shown in fig. 1, a fuel performance analysis and calculation method for a lead-based fast reactor oxide reactor is provided, and this embodiment is illustrated by applying this method to a terminal, it is to be understood that this method may also be applied to a server, and may also be applied to a system including a terminal and a server, and is implemented by interaction between the terminal and the server. The calculation method for fuel element performance analysis provided by the embodiment can be used for not only reactor fuel element performance analysis and calculation, but also other fields for analyzing and calculating the performance of other fuel elements, for example, analyzing and calculating a sodium-cooled fast reactor and analyzing and calculating a pressurized water reactor oxide fuel rod. In this embodiment, the method includes the steps of:

step 1, generating a time sequence of a fuel rod to be analyzed, and axially dividing a geometric structure of the fuel rod into different axial segments;

step 2, carrying out global calculation on the fuel rod to be analyzed in each time step, and carrying out thermal coupling analysis;

step 3, local calculation is carried out on different axial subsections of the fuel rod after the thermodynamic coupling analysis, and multi-physical field analysis is realized; the multi-physics include fuel reconstitution, component redistribution, fission gas release and swelling, cladding corrosion, and core chemical interactions.

Specifically, the method described in the embodiment of the present invention takes the fast neutron reactor startup condition as an example, and as shown in fig. 2, generating the time sequence of the fuel rod to be analyzed refers to setting time steps of different behavior models of the fuel rod on the premise of ensuring calculation stability and accuracy, setting the time sequence according to the irradiation history of the reactor, and allocating and controlling execution of each calculation module.

Dividing the geometric structure of the fast reactor fuel rod into different axial segments in the axial direction by adopting a 1.5-dimensional axial stacking assumption, dispersing a calculation region into node rings which are mutually nested in the radial direction to generate a calculation grid for fuel rod simulation, and performing dispersion solution on global calculation and local calculation by a finite volume method; a global thermodynamic coupling + fuel performance analysis of the local behavior model is performed for each time step.

In the step 2, the global calculation of the fuel rod to be analyzed in each time step includes the following steps:

(1) calculating the pre-estimated temperature distribution in the fuel rod under the current working condition, wherein the pre-estimated temperature distribution comprises core cladding temperature distribution, clearance heat transfer and coolant axial temperature distribution;

the method specifically comprises the following steps: calculating the power density of a fuel body according to input conditions and initial parameters, performing global heat transfer analysis on pellets, cladding and coolant of the fuel rod, and solving to obtain the estimated temperature distribution inside the fuel rod under the current working condition by establishing a pellet solid heat conduction equation, a cladding solid heat conduction equation and a coolant axial energy equation of core-cladding clearance heat exchange heat flow and convection heat exchange heat flow of the coolant by adopting a full principal component Gauss if elimination method, wherein the solved fuel rod diameter and temperature distribution is shown in figure 3;

q_g＝2πr_gaph_G+J(T_fo-T_ci)，q_f＝2πr_coh_F(T_l-T_co) (1)

in the formula: q. q.s_gFor pellet-cladding gap heat flux, q_fIs the cladding-coolant interface heat flux; r is_gap，r_coThe average radius of the core cladding gap and the outer radius of the cladding are respectively; h is_G+J，h_FThe heat exchange coefficients of the core cladding gaps and the coolant are respectively; t is_fo，T_ci，T_l，T_coRespectively the temperature of the outer surface of the pellet, the temperature of the inner surface of the cladding, the temperature of the coolant and the temperature of the outer surface of the cladding; pi represents a circumferential ratio;

in the formula: rho is the material density; c is the specific heat capacity of the material; t is the temperature; t is time; r is the radius; λ is the material thermal conductivity; q is a volumetric heat source (only pellet portion is present);

in the formula: a. the_lSingle rod single channel coolant flow area; rho_lIs the coolant density; c. C_lIs the coolant heat capacity; t is_lIs the coolant temperature; t is time; w is the coolant axial flow rate; z is the axial coordinate.

(2) According to the pre-estimated temperature distribution inside the fuel rod, calculating to obtain the initial mechanical analysis under the current pre-estimated temperature, wherein the initial mechanical analysis comprises stress distribution of pellets and cladding, node elastoplasticity, creep, swelling strain, radial displacement and axial extension;

the method specifically comprises the following steps: performing stress-strain analysis through the estimated temperature distribution of the fuel rod obtained by calculation, starting from a radial balance equation, a compatibility equation and a stress-strain constitutive equation under a column coordinate, establishing a corresponding relation between displacement and strain and a corresponding relation between stress and displacement by adopting a displacement method, establishing a continuity equation at the boundary of each radial circular ring control body according to the continuity of the stress and the displacement, and performing simultaneous boundary condition coupling solution to obtain preliminary mechanical analysis under the current estimated temperature, wherein the preliminary mechanical analysis is shown in formulas (4) - (8), the internal stress and the displacement distribution of the fuel and the cladding can be obtained through mechanical analysis, and the preliminary mechanical analysis is shown in figures 4 and 5, so that the cracking, the healing, the deformation and the cladding failure of the pellet are analyzed and predicted.

In the formula: u (r) is the nodal radial displacement; c_1i，C_2iRespectively are integral constants; v is the Poisson's ratio; α is a thermal expansion coefficient;respectively controlling swelling strain of the body i, radial direction inelastic strain and annular direction inelastic strain (creep deformation + plastic strain); t is₀Is a reference temperature;

in the formula: sigma_rIs the radial stress; e is Young's modulus;is the axial average strain;

(3) judging whether the core cladding contact is converged according to the stress distribution of the core pellets and the cladding; if the pressure is converged, the pressure of the air cavity in the current state is calculated according to the estimated temperature distribution, whether the pressure of the air cavity is converged or not is judged, and local calculation is carried out if the pressure is converged.

The criterion for judging whether the core bag contact is converged is as follows: adjusting the contact pressure load until whether the invasion depth of the core package clearance meets a first preset value or not, and converging if the invasion depth meets the first preset value;

the method specifically comprises the following steps: judging whether core package contact occurs according to deformation conditions of the core packages and the cladding obtained by the preliminary mechanical analysis, if so, executing contact pressure iteration, and continuously adjusting contact pressure load until the intrusion depth of the core package gap meets a convergence criterion;

the criterion for judging whether the air cavity pressure is converged is as follows: whether the pressure of the air cavity meets a second preset value or not, and if so, convergence is performed;

the method specifically comprises the following steps: and (3) performing heat transfer analysis on the fuel rod under the current geometric structure through the obtained deformation of the fuel rod, correcting the temperature distribution of the core cladding, the gap heat exchange and the axial temperature distribution of the coolant, calculating the pressure of an air cavity under the current state, and repeatedly performing the steps (1) to (3) until convergence finishes the final thermal coupling analysis under the current time step when the pressure of the air cavity does not meet the convergence criterion.

In the step 3, the local calculation is performed on the different axial segments of the fuel rod after the thermal coupling analysis, and the method comprises the following steps:

(1) and (3) fuel reconfiguration: calculating pore migration, central opening and grain growth caused by high temperature and large temperature gradient;

the method specifically comprises the following steps: solving a fuel porosity mobility equation and a grain growth model through coupled thermodynamic analysis, and calculating pore mobility (shown in figure 6), central opening and grain growth caused by high temperature and large temperature gradient;

(2) redistribution of components: solving the change of O/M ratio and stoichiometric state of the fuel caused by the migration and transportation of oxygen and actinides in the fuel; o represents oxygen element, M represents heavy metal element, and the O/M ratio refers to the ratio of oxygen element to heavy metal element in the chemical components of the reactor fuel;

the method specifically comprises the following steps: solving, by coupled thermodynamic analysis, the changes in oxygen and actinide transport and transport inside the fuel that result in the fuel O/M ratio (as shown in fig. 7) and the stoichiometric state;

(3) fission gas release and swelling: calculating and analyzing the generation, nucleation, growth, polymerization, re-dissolution and fuel swelling phenomena caused by the interaction process with grain boundaries and defects of insoluble and volatile gases in the fuel;

(4) cladding corrosion and core chemical interaction: and (4) calculating and analyzing corrosion of the outer wall surface of the cladding caused by liquid metal coolant scouring and chemical reaction and the corrosion process of the inner wall surface FCCI.

And repeatedly executing the steps until the irradiation history is finished, completing the performance analysis of the lead-based fast reactor oxide fuel element and outputting a simulation calculation result.

Preferably, before the step of generating a time series of fuel rods to be analyzed, the method of the invention further comprises: the active segment, the air cavity and the corresponding cladding part of the fast reactor fuel rod are used as analysis and simulation objects, the geometric structure, the material physical property and the reactor operation condition of the fast reactor fuel rod are input, and the actual operation condition and the irradiation history of the fuel rod are determined.

The method specifically comprises the following steps: taking the active segment, the air cavity and the corresponding cladding part of the fast reactor fuel rod as analysis and simulation objects, and inputting parameters such as the inner and outer diameters of the pellet and the cladding, the height of the air cavity, the P/D ratio and the like so as to determine a calculation area; inputting the types of the core blocks and the cladding materials, initial processing parameters and the types of the cooling agents, and matching a material library to determine a research object; the fuel rod line power, the fission rate, the neutron fluence rate history, the coolant flux variation, etc. are input to determine the actual operating conditions and irradiation history of the nuclear fuel rod.

As shown in FIG. 8, in one embodiment of the present invention, a reactor fuel performance analysis computing system is provided, comprising: the system comprises a space-time discrete module, a global calculation module and a local calculation module; the space-time discrete module generates a time sequence of the fuel rod to be analyzed and divides the geometric structure of the fuel rod into different axial segments in the axial direction; the global calculation module is used for carrying out global calculation on the fuel rod to be analyzed in each time step and carrying out thermal coupling analysis; the local calculation module is used for carrying out local calculation on different axial subsections of the fuel rod after the thermal coupling analysis so as to realize multi-physical field analysis; the multi-physics include fuel reconstitution, component redistribution, fission gas release and swelling, cladding corrosion, and core chemical interactions.

Before executing the space-time discrete module, the system of the invention also comprises a preprocessing module; the pretreatment module is used for taking an active section, an air cavity and a corresponding cladding part of the fast reactor fuel rod as analysis and simulation objects, inputting the geometric structure, material physical properties and reactor operation conditions of the fast reactor fuel rod, and determining the actual operation condition and irradiation history of the fuel rod.

The system provided in this embodiment is used for executing the above method embodiments, and for details of the process and the details, reference is made to the above embodiments, which are not described herein again.

The invention establishes a serial coupling mode and algorithm logic of behavioral models of fast reactor fuel full-rod thermal analysis and fuel reconstruction, component redistribution, fission gas release, cladding corrosion, core chemical interaction and the like, and performs steady-state analysis and simulation calculation on lead-based fast reactor oxide fuel elements. The method has the advantages that multiple behaviors of the fuel pellets and the cladding in the stack are coupled, and the evolution of important characteristics along with irradiation time is tracked, so that the performance of the fuel rod under various operating conditions is predicted, reference is provided for lead-based fast stack design and research, and basis is provided for experimental layout.

As shown in fig. 9, which is a schematic structural diagram of a computing device provided in an embodiment of the present invention, the computing device may be a terminal, and may include: a processor (processor), a communication Interface (communication Interface), a memory (memory), a display screen and an input device. The processor, the communication interface and the memory are communicated with each other through a communication bus. The processor is used to provide computing and control capabilities. The memory includes a non-volatile storage medium, an internal memory, the non-volatile storage medium storing an operating system and a computer program that when executed by the processor implements an analytical computation method; the internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The communication interface is used for carrying out wired or wireless communication with an external terminal, and the wireless communication can be realized through WIFI, a manager network, NFC (near field communication) or other technologies. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device can be a touch layer covered on the display screen, a key, a track ball or a touch pad arranged on a shell of the computing equipment, an external keyboard, a touch pad or a mouse and the like. The processor may call logic instructions in memory to perform the following method:

generating a time sequence of the fuel rod to be analyzed, and axially dividing the geometric structure of the fuel rod into different axial segments; carrying out global calculation on the fuel rod to be analyzed in each time step, and carrying out thermal coupling analysis; local calculation is carried out on different axial subsections of the fuel rod after the thermodynamic coupling analysis, and multi-physical field analysis is realized; the multi-physics include fuel reconstitution, component redistribution, fission gas release and swelling, cladding corrosion, and core chemical interactions.

In addition, the logic instructions in the memory may be implemented in the form of software functional units and may be stored in a computer readable storage medium when sold or used as a stand-alone product. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

Those skilled in the art will appreciate that the architecture shown in fig. 9 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects may be applied, and that a particular computing device may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.

In one embodiment of the invention, a computer program product is provided, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions that, when executed by a computer, enable the computer to perform the methods provided by the above-described method embodiments, for example, comprising: generating a time sequence of the fuel rod to be analyzed, and axially dividing the geometric structure of the fuel rod into different axial segments; carrying out global calculation on the fuel rod to be analyzed in each time step, and carrying out thermal coupling analysis; local calculation is carried out on different axial subsections of the fuel rod after the thermodynamic coupling analysis, and multi-physical field analysis is realized; the multi-physics include fuel reconstitution, component redistribution, fission gas release and swelling, cladding corrosion, and core chemical interactions.

In one embodiment of the invention, a non-transitory computer-readable storage medium is provided, which stores server instructions that cause a computer to perform the methods provided by the above embodiments, for example, including: generating a time sequence of the fuel rod to be analyzed, and axially dividing the geometric structure of the fuel rod into different axial segments; carrying out global calculation on the fuel rod to be analyzed in each time step, and carrying out thermal coupling analysis; local calculation is carried out on different axial subsections of the fuel rod after the thermodynamic coupling analysis, and multi-physical field analysis is realized; the multi-physics include fuel reconstitution, component redistribution, fission gas release and swelling, cladding corrosion, and core chemical interactions.

The implementation principle and technical effect of the computer-readable storage medium provided by the above embodiments are similar to those of the above method embodiments, and are not described herein again.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.