Sodium-water reaction accident simulation method and system for sodium-cooled fast reactor

Abstract

The invention provides a sodium-water reaction accident simulation method and system for a sodium-cooled fast reactor, and the method comprises the steps: constructing a sodium-water reaction model which comprises a tiny sodium-water reaction model and a large sodium-water reaction model; a sodium-water reaction simulation instruction is obtained, a target sodium-water reaction model is determined based on a reaction type identifier in the sodium-water reaction simulation instruction, and the target sodium-water reaction model is the small sodium-water reaction model or the large sodium-water reaction model; simulating a sodium-water reaction accident based on the target sodium-water reaction model to obtain a sodium-water reaction simulation result; and inputting the sodium-water reaction simulation result into a full-reactor simulation model to obtain a full-reactor accident response result. According to the invention, the accuracy of the sodium-water reaction simulation result and the whole reactor accident response result is improved.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear power simulation, and in particular to a sodium-water reaction accident simulation method and system for a sodium-cooled fast reactor. Background Art

[0002] The occurrence of sodium-water reaction accidents will affect the operating safety of the entire sodium-cooled fast reactor. Therefore, sodium-water reaction accidents are important accidents that must be considered in the design and safety analysis of sodium-cooled fast reactors.

[0003] The conventional means to avoid sodium-water reaction accidents in the prior art is to use a mature micro-hydrogen detection method, that is, to detect the hydrogen concentration through a highly sensitive detector to determine whether a sodium-water reaction accident has occurred in a sodium-cooled fast reactor. This requires a high sensitivity of the detector, and it is impossible to fully simulate and analyze sodium-water. Therefore, a technical solution for simulating sodium-water reaction accidents is proposed in the prior art. However, the current research on sodium-water reaction accidents is still in an imperfect stage, and the one-dimensional characteristic line method is generally used to simulate the sodium-water reaction, and the simulation results are inaccurate.

[0004] Therefore, there is an urgent need to provide a sodium-water reaction accident simulation method and system for a sodium-cooled fast reactor to improve the accuracy of simulation results for sodium-water reaction accidents. Summary of the invention

[0005] In view of this, it is necessary to provide a sodium-water reaction accident simulation method and system for a sodium-cooled fast reactor to achieve accurate description of the sodium-water reaction, so as to solve the technical problem in the prior art of inaccurate description of the sodium-water reaction, resulting in inaccurate simulation results of the sodium-water reaction accident.

[0006] On the one hand, in order to solve the above technical problems, the present invention provides a sodium-water reaction accident simulation method for a sodium-cooled fast reactor, comprising: Constructing a sodium-water reaction model, wherein the sodium-water reaction model includes a small sodium-water reaction model and a large sodium-water reaction model; Obtaining a sodium-water reaction simulation instruction, and determining a target sodium-water reaction model based on a reaction type identifier in the sodium-water reaction simulation instruction, wherein the target sodium-water reaction model is the tiny sodium-water reaction model or the large sodium-water reaction model; Simulating a sodium-water reaction accident based on the target sodium-water reaction model to obtain a sodium-water reaction simulation result; The sodium-water reaction simulation results are input into a full-heap simulation model to obtain full-heap accident response results.

[0007] In a possible implementation, the small sodium-water reaction model is a reaction model corresponding to a small leakage, where the hydrogen concentration in the sodium gas in the secondary circuit exceeds 0.17×10 -6 , and / or, the hydrogen concentration in the argon gas exceeds 0.07×10-2 Leakage situation at the time of The large sodium water reaction model is a reaction model corresponding to a large leakage. A large leakage is a leakage when any two of the following three situations occur: the argon pressure in the buffer tank in the secondary circuit exceeds 0.34MPa or is lower than 0.26MPa, the sodium liquid level in the buffer tank reaches an increase of 20cm or an increase of 5cm / s, and the difference in sodium flow at the inlet and outlet of the steam generator reaches 20% of the normal flow.

[0008] In a possible implementation, the tiny sodium-water reaction model is: ; ; ; In the formula, is a one-way reaction identifier; is a reversible reaction identifier.

[0009] In a possible implementation, when the target sodium-water reaction model is a tiny sodium-water reaction model, the simulation based on the target sodium-water reaction model to obtain a sodium-water reaction simulation result includes: Obtaining a first water leakage rate; Determine the hydrogen ion yield based on the first water leakage rate and the tiny sodium-water reaction model; Among them, the first water leakage rate is regarded as a complete response.

[0010] In a possible implementation, the large sodium water reaction model includes a reaction heat generation calculation model, a spherical bubble growth calculation model and a cylindrical bubble growth model; The reaction heat generation calculation model is: ; ; The calculation model of spherical bubble growth is: ; ; ; ; ; ; ; ; The cylindrical bubble growth model is: ; ; ; ; ; ; ; In the formula, Produce heat for the reaction; The chemical heat of reaction is to produce - mole of hydrogen; is the amount of hydrogen produced; is the amount of leaked water generated; is the ratio of hydrogen production to the amount of water leaked; is the internal temperature of the bubble; For time; is the initial temperature of the hydrogen produced in the reaction; It is a parameter to characterize the physical properties of hydrogen; is the bubble volume; The quality of the leaked water; is the pressure inside the bubble; is the bubble radius; is the radial velocity of liquid sodium due to bubble growth and extrusion; is the liquid sodium pressure at the sodium-hydrogen interface; , are the flow rates of liquid sodium on the left and right sides of the bubble respectively; , is the growth rate of the left and right sides of the bubble; , is the pressure of liquid sodium on the left and right sides of the bubble; is the drag coefficient caused by viscosity; is the time step; is the characteristic line value on the left side of the bubble; is the characteristic line value on the right side of the bubble; is the characteristic length; is the growth rate of the bubble; is the length of the bubble.

[0011] In a possible implementation, when the target sodium-water reaction model is a large sodium-water reaction model, simulation is performed based on the target sodium-water reaction model to obtain a sodium-water reaction simulation result, including: Obtain the pressure difference in the third-loop steam generator in the core area of ​​the large sodium water reaction of the second loop; determining a second water leakage rate based on the pressure difference; Obtain the secondary circuit temperature and secondary circuit pressure at both ends of the steam generator pipe section specified by the rupture; The reaction heat release, the flow change of the sodium circuit during the reaction, the reactant consumption rate, the reaction product composition, the reaction product generation rate and the pressure fluctuation of the sodium circuit in the initial stage of the reaction are determined based on the secondary circuit temperature, the secondary circuit pressure, the second water leakage rate and the large sodium-water reaction model.

[0012] In a possible implementation, determining a second water leakage rate based on the pressure difference includes: Determining whether the pressure difference is greater than a pressure difference threshold; When the pressure difference is greater than the pressure difference threshold, determining a second water leakage rate based on a critical leakage flow calculation method; When the pressure difference is less than or equal to the pressure difference threshold, a second water leakage rate is determined based on a preset leakage calculation model.

[0013] In a possible implementation, inputting the sodium-water reaction simulation result into a full-stack simulation model to obtain a full-stack accident response result includes: Step 1: Obtain simulation control variables; Step 2, obtaining the reactor operating conditions at the last time step or the initial moment; Step 3: obtaining a reactor SimTherm simulation model, and inputting the simulation control variables, the reactor operating conditions at the previous time step or the initial moment, and the sodium-water reaction simulation results into the reactor SimTherm simulation model for coupling calculation to obtain a full-reactor accident response result; Step 4: Determine whether a simulation pause signal is received and whether a preset simulation time has been reached; Step 5: If the simulation pause signal is received or the preset simulation time is reached, then the simulation is ended; if the simulation pause signal is not received and the preset simulation time is not reached, then the process returns to step 2.

[0014] In a possible implementation, the sodium-water reaction accident simulation method for a sodium-cooled fast reactor further includes: Sodium-water reaction accident reference data is obtained, and the accuracy of the sodium-water reaction model is verified based on the sodium-water reaction accident reference data and the full-stack accident response result.

[0015] On the other hand, the present invention also provides a sodium-water reaction accident simulation system for a sodium-cooled fast reactor, comprising: A sodium-water reaction model construction unit, used to construct a sodium-water reaction model, wherein the sodium-water reaction model includes a small sodium-water reaction model and a large sodium-water reaction model; a sodium-water reaction model selection unit, configured to obtain a sodium-water reaction simulation instruction, and determine a target sodium-water reaction model based on a reaction type identifier in the sodium-water reaction simulation instruction, wherein the target sodium-water reaction model is a small sodium-water reaction model or a large sodium-water reaction model; A sodium-water reaction simulation unit, used to perform simulation based on the target sodium-water reaction model to obtain a sodium-water reaction simulation result; The whole-stack accident simulation unit is used to input the sodium-water reaction simulation result into the whole-stack simulation model to obtain the whole-stack accident response result.

[0016] The beneficial effects of the present invention are as follows: the sodium-water reaction accident simulation method of the sodium-cooled fast reactor provided by the present invention, by respectively constructing a micro sodium-water reaction model and a large sodium-water reaction model, describes the sodium-water reaction process and mechanism in a fine and accurate manner, thereby improving the accuracy of the sodium-water reaction simulation results and the full-reactor accident response results determined by the constructed sodium-water reaction model. Furthermore, the present invention couples the sodium-water reaction model with the full-reactor simulation model to describe the influence of the sodium-water reaction on the entire sodium-cooled fast reactor, thereby realizing the full-reactor simulation of the sodium-cooled fast reactor and improving the overall simulation accuracy of the sodium-cooled fast reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic diagram of the structure of an embodiment of a simplified secondary circuit cooling system provided by the present invention; Figure 2 A schematic flow chart of an embodiment of a sodium-water reaction accident simulation method for a sodium-cooled fast reactor provided by the present invention; Figure 3 For the present invention Figure 2 A schematic flow chart of an embodiment of step S203; Figure 4 For the present invention Figure 3 A schematic flow chart of an embodiment of step S302; Figure 5 For the present invention Figure 2 A schematic flow chart of an embodiment of step S204; Figure 6 The present invention provides a schematic structural diagram of an embodiment of a sodium-water reaction accident simulation system for a sodium-cooled fast reactor. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0020] It should be understood that the schematic drawings are not drawn to scale. The flowchart used in the present invention shows the operations implemented according to some embodiments of the present invention. It should be understood that the operations of the flowchart can be implemented out of order, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art, under the guidance of the content of the present invention, can add one or more other operations to the flowchart, and can also remove one or more operations from the flowchart. Some of the block diagrams shown in the accompanying drawings are functional entities, which do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor systems and / or microcontroller systems.

[0021] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] The present invention provides a sodium-water reaction accident simulation method and system for a sodium-cooled fast reactor, which are respectively described below.

[0023] Before presenting the embodiments, it should be noted that the sodium-water reaction accident simulation method and system of the sodium-cooled fast reactor in the embodiments of the present invention are mainly used to simulate the secondary cooling system of the sodium-cooled fast reactor. Figure 1As shown in the figure, the simplified secondary circuit cooling system includes 1 sodium circulation pump (secondary circuit pump), 1 buffer tank, 1 distributor, 2 intermediate heat exchangers, 2 steam generator modules, and sodium side bursting membranes and gas side bursting membranes. The secondary circuit pump is arranged in the reactor building and is the power source for the flow of the secondary circuit medium. The intermediate heat exchanger is arranged in the main reactor container, and its heat exchange tube is the pressure boundary between the primary circuit and the secondary circuit. The steam generator module includes an evaporator and a superheater, and the steam generator module is arranged in the steam generator building. The buffer tank is in the steam generator building and is mainly used to compensate for the change in sodium volume caused by temperature changes in the system. The distributor is arranged in the steam generator building and is used to evenly distribute the sodium in the secondary circuit main pipeline to each group of steam generator modules so that the sodium flow entering each group of steam generator modules is consistent.

[0024] Working process of the secondary circuit main cooling system: When the secondary circuit system is operating at rated conditions, the sodium temperature of the cold section of the secondary circuit system is 308℃. The sodium in the entire secondary circuit is driven by the sodium circulation pump to circulate. When the cold sodium flows through the tube side of the intermediate heat exchanger, it exchanges heat with the sodium in the primary circuit in the shell side of the intermediate heat exchanger. When the sodium that has absorbed the heat of the primary circuit flows out of the intermediate heat exchanger, the temperature rises to 505℃. The hot sodium enters the distributor and is divided into eight branches through the distributor to flow into eight groups of steam generators. After flowing through the steam generator and transferring heat to the water / steam system, the sodium temperature drops to 308℃ again. Then the cold sodium of the eight branches converges into the sodium buffer tank, and then flows from the buffer tank into the sodium circulation pump. The sodium is pressed into the tube side of the intermediate heat exchanger again through the sodium circulation pump, and finally the material circulation and energy transfer of the entire secondary circuit system are realized.

[0025] Figure 2 A schematic flow chart of an embodiment of a sodium-water reaction accident simulation method for a sodium-cooled fast reactor provided by the present invention is shown in FIG. Figure 2 As shown, the sodium-water reaction accident simulation method of the sodium-cooled fast reactor includes: S201, constructing a sodium-water reaction model, wherein the sodium-water reaction model includes a small sodium-water reaction model and a large sodium-water reaction model; S202, obtaining a sodium-water reaction simulation instruction, and determining a target sodium-water reaction model based on a reaction type identifier in the sodium-water reaction simulation instruction, wherein the target sodium-water reaction model is a small sodium-water reaction model or a large sodium-water reaction model; S203, performing simulation based on the target sodium-water reaction model to obtain a sodium-water reaction simulation result; S204, inputting the sodium-water reaction simulation result into the full-heap simulation model to obtain the full-heap accident response result.

[0026] In a specific embodiment, the reaction type identifier in step S202 may be 1. When the reaction type identifier is 0, the target sodium-water reaction model is a small sodium-water reaction model. When the reaction type identifier is 1, the target sodium-water reaction model is a large sodium-water reaction model.

[0027] In another specific embodiment, the number of reaction type identifiers in step S202 is two, and the two reaction type identifiers are used to identify the small sodium-water reaction model and the large sodium-water reaction model, respectively.

[0028] It should be understood that the sodium-water reaction simulation instruction also includes the breach location, that is, the specific location where the sodium-water reaction occurs in the secondary circuit cooling system.

[0029] It should be noted that the sodium-water reaction accident simulation method of the sodium-cooled fast reactor in the embodiment of the present invention is based on the RINSIM simulation platform. Among them, the RINSIM simulation platform is a software environment for simulator development and operation built on the Windows / Linux operating system. It is the basis for the simulation of a simulator process system and constitutes a full-range simulator with DCSFSS. As a tool for the entire simulator manufacturing process such as simulator development, debugging, and operation, the RINSIM simulation platform includes multiple functional modules with a global shared database as the core, providing support for the entire simulator cycle such as simulation model software development and maintenance, simulation development system combination, simulator real-time operation, and software debugging.

[0030] It should also be noted that the sodium-water reaction caused by the medium-break accident is only an intermediate transition accident state in the entire sodium-water reaction accident sequence, and will evolve into a large sodium-water reaction accident in a relatively short period of time. Therefore, the design of this accident condition is not considered in the embodiment of the present invention, and only the two relatively stable accident conditions of the small sodium-water reaction accident and the large sodium-water reaction accident are modeled and calculated.

[0031] Compared with the prior art, the sodium-water reaction accident simulation method provided in the embodiment of the present invention, by respectively constructing a micro sodium-water reaction model and a large sodium-water reaction model, describes the sodium-water reaction process and mechanism in a fine and accurate manner, thereby improving the accuracy of the sodium-water reaction simulation results and the full-reactor accident response results determined by the constructed sodium-water reaction model. Furthermore, the embodiment of the present invention achieves full-reactor simulation of the sodium-cooled fast reactor by coupling the sodium-water reaction model with the full-reactor simulation model to describe the influence of the sodium-water reaction on the entire sodium-cooled fast reactor, thereby improving the overall simulation accuracy of the sodium-cooled fast reactor.

[0032] In some embodiments of the present invention, the small sodium-water reaction model refers to a reaction model corresponding to a small leakage, and a small leakage refers to a hydrogen concentration in the sodium gas in the secondary circuit exceeding 0.17×10 -6, and / or, the hydrogen concentration in the argon gas exceeds 0.07×10 -2 The large sodium-water reaction model refers to the reaction model corresponding to the large leakage. The large leakage refers to the leakage when any two of the following three situations occur: the argon pressure in the buffer tank in the secondary circuit exceeds 0.34MPa or is lower than 0.26MPa, the sodium liquid level in the buffer tank reaches an increase of 20cm or an increase of 5cm / s, and the difference in sodium flow at the inlet and outlet of the steam generator reaches 20% of the normal flow.

[0033] The embodiment of the present invention defines a large leak as a leak when any two of the three situations occur, so that the large leak meets the multiplicity principle, thereby improving the selection accuracy and reliability of the large sodium-water reaction model.

[0034] In some embodiments of the present invention, the small sodium-water reaction model is: ; ; ; The first formula describes the sodium-water reaction at the leak point. and The second formula describes the process of and The third formula describes the dissolution process of hydrogen.

[0035] In the series of processes described by the above three chemical reaction equations, when the leakage rate of all leaked water is regarded as a complete reaction, the production rate (mol / s) of sodium hydroxide and hydrogen can be obtained according to the reaction equation. This production rate is divided by the cross-sectional area and flow rate, that is, the instantaneous ion concentration of each reaction product in the cross-sectional area of ​​the leakage point.

[0036] In other words, in some embodiments of the present invention, when the target sodium-water reaction model is a small sodium-water reaction model, step S203 includes: Obtaining a first water leakage rate; Determine the hydrogen ion yield based on the first water leakage rate and the tiny sodium-water reaction model; Among them, the first water leakage rate is regarded as a complete response.

[0037] It should be understood that the first water leakage rate can be determined by the amount of hydrogen that can be completely dissolved in the loop. For example, the maximum hydrogen production rate corresponding to the amount of hydrogen that can be completely dissolved in the branch is about 0.08 g / s, and the corresponding first water leakage rate is about 3 g / s.

[0038] In some embodiments of the present invention, in order to simplify the calculation, the following simplified assumptions are made for the sodium-water reaction model: When the heat exchange tube ruptures, since the water pressure in the third circuit is much greater than the pressure of the liquid sodium in the second circuit, it is believed that cooling water or high-pressure water vapor will flow into the liquid sodium space from the rupture point, and the rupture flow rate is calculated according to the critical flow model.

[0039] The sodium-water reaction proceeds very quickly, and the amount of liquid sodium is sufficient. If all the leaked water is considered, the reaction will be completed instantly.

[0040] The hydrogen generated by the reaction is regarded as an ideal gas and is insulated from the surrounding liquid sodium in a very short time. All the heat released in the sodium-water reaction is used for the expansion and growth of hydrogen bubbles.

[0041] Since the growth of hydrogen bubbles is involved in the reaction process of large sodium water, in order to further improve the accuracy of the large sodium water reaction model constructed in the embodiments of the present invention, in some embodiments of the present invention, based on the shape of the bubbles, the large sodium water reaction model includes a reaction heat generation calculation model, a spherical bubble growth calculation model and a cylindrical bubble growth model.

[0042] Among them, the reaction heat generation calculation model is: ; ; The calculation model of spherical bubble growth is: ; ; ; ; ; ; ; ; The cylindrical bubble growth model is: ; ; ; ; ; ; ; In the formula, Produce heat for the reaction; The chemical heat of reaction is to produce - mole of hydrogen; is the amount of hydrogen produced; is the amount of leaked water; is the ratio of hydrogen production to the amount of water leaked; is the internal temperature of the bubble; For time; is the initial temperature of the hydrogen produced in the reaction; It is a parameter to characterize the physical properties of hydrogen; is the bubble volume; The quality of the leaked water; is the pressure inside the bubble; is the bubble radius; is the radial velocity of liquid sodium due to bubble growth and extrusion; is the liquid sodium pressure at the sodium-hydrogen interface; , are the flow rates of liquid sodium on the left and right sides of the bubble respectively; , is the growth rate of the left and right sides of the bubble; , is the pressure of liquid sodium on the left and right sides of the bubble; is the drag coefficient caused by viscosity; is the time step; is the characteristic line value on the left side of the bubble; is the characteristic line value on the right side of the bubble; is the characteristic length; is the growth rate of the bubble; is the length of the bubble.

[0043] It should be noted that based on the spherical bubble growth calculation model, P, V, T, r, P R 、u r , u1, u2, these eight unknown quantities can be solved based on the cylindrical bubble growth model to obtain P, V, T, h, u r , u1, u2 these 7 unknown quantities.

[0044] In some embodiments of the present invention, when the target sodium-water reaction model is a large sodium-water reaction model, such as Figure 3 As shown, step S203 includes: S301, obtaining the pressure difference in the third-loop steam generator in the core area of ​​the large sodium water reaction of the second loop; S302, determining a second water leakage rate based on the pressure difference; S303, obtaining the secondary circuit temperature and secondary circuit pressure at both ends of the steam generator pipe section specified by the rupture; S304, based on the secondary circuit temperature, the secondary circuit pressure, the second water leakage rate and the large sodium-water reaction model, determine the reaction heat release, the flow change of the sodium circuit during the reaction, the reactant consumption rate, the reaction product composition, the reaction product generation rate and the pressure fluctuation of the sodium circuit in the initial stage of the reaction.

[0045] The embodiment of the present invention determines the second water leakage rate based on the pressure difference, and can determine the accuracy of the second water leakage rate, thereby improving the accuracy of the determined sodium-water reaction simulation result.

[0046] In some embodiments of the present invention, Figure 4 As shown, step S302 includes: S401, determining whether the pressure difference is greater than a pressure difference threshold; S402, when the pressure difference is greater than the pressure difference threshold, determining a second water leakage rate based on a critical leakage flow calculation method; S403: When the pressure difference is less than or equal to the pressure difference threshold, determine a second water leakage rate based on a preset leakage calculation model.

[0047] Among them, the water leakage rate in the preset leakage calculation model is related to the flow rate of the inlet and outlet, and in the critical leakage calculation method, the water leakage rate is a certain value and has nothing to do with the flow rate of the inlet and outlet.

[0048] It should be noted that the preset leakage calculation model and critical leakage calculation method are both built into the SimTherm program.

[0049] In a specific embodiment of the present invention, the pressure difference threshold is 5.47 MPa.

[0050] In some embodiments of the present invention, Figure 5 As shown, step S204 includes: S501, obtaining simulation control variables; S502, obtaining the reactor operating conditions at the last time step or the initial moment; S503, obtaining a reactor SimTherm simulation model, and inputting simulation control variables, reactor operating conditions at the previous time step or initial moment, and sodium-water reaction simulation results into the reactor SimTherm simulation model for coupling calculation to obtain a full-reactor accident response result; S504, determining whether a simulation pause signal is received and whether a preset simulation time is reached; S505: If a simulation pause signal is received or the preset simulation time is reached, the simulation is terminated; if no simulation pause signal is received and the preset simulation time is not reached, the process returns to S502.

[0051] The simulation suspension signal in step S504 is a signal for suspending the reactor simulation operation sent by the simulation personnel.

[0052] It should be understood that an input-output interface can be constructed between the reactor SimTherm simulation model and the sodium-water reaction model, and data transmission between the two models can be achieved through the input-output interface.

[0053] In order to verify the validity of the sodium-water reaction model constructed in the embodiment of the present invention, in some embodiments of the present invention, the sodium-water reaction accident simulation method of the sodium-cooled fast reactor further includes: Obtain sodium-water reaction accident reference data, and verify the accuracy of the sodium-water reaction model based on the sodium-water reaction accident reference data and the full-reactor accident response results.

[0054] Among them, the reference data for sodium-water reaction accidents can be the data provided by the Nuclear Power Operation Research Institute.

[0055] Specifically, the whole-stack accident response result is each result parameter in steps S203 and S304.

[0056] The embodiment of the present invention uses the sodium-water reaction accident reference data to verify the accuracy of the sodium-water reaction model, which can further ensure the accuracy and effectiveness of the constructed sodium-water reaction model.

[0057] In order to better implement the sodium-water reaction accident simulation method of the sodium-cooled fast reactor in the embodiment of the present invention, based on the sodium-water reaction accident simulation method of the sodium-cooled fast reactor, the embodiment of the present invention also provides a sodium-water reaction accident simulation system of the sodium-cooled fast reactor, such as Figure 6 As shown, the sodium-water reaction accident simulation system 600 of the sodium-cooled fast reactor includes: A sodium-water reaction model building unit 601 is used to build a sodium-water reaction model, wherein the sodium-water reaction model includes a small sodium-water reaction model and a large sodium-water reaction model; The sodium-water reaction model selection unit 602 is used to obtain a sodium-water reaction simulation instruction and determine a target sodium-water reaction model based on a reaction type identifier in the sodium-water reaction simulation instruction, wherein the target sodium-water reaction model is a small sodium-water reaction model or a large sodium-water reaction model; A sodium-water reaction simulation unit 603 is used to perform simulation based on a target sodium-water reaction model to obtain a sodium-water reaction simulation result; The whole-stack accident simulation unit 604 is used to input the sodium-water reaction simulation results into the whole-stack simulation model to obtain the whole-stack accident response results.

[0058] It should be noted that the sodium-water reaction accident simulation system 600 for a sodium-cooled fast reactor provided in the above embodiment can implement the technical solution described in the above embodiment of the sodium-water reaction accident simulation method for a sodium-cooled fast reactor. The specific implementation principles or specific implementation details of the above modules or units can refer to the corresponding contents in the above embodiment of the sodium-water reaction accident simulation method for a sodium-cooled fast reactor.

[0059] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0060] The sodium-water reaction accident simulation method and system for a sodium-cooled fast reactor provided by the present invention are introduced in detail above. Specific examples are used herein to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A sodium-water reaction accident simulation method for a sodium-cooled fast reactor, characterized in that: include: Constructing a sodium-water reaction model, wherein the sodium-water reaction model includes a small sodium-water reaction model and a large sodium-water reaction model; Obtaining a sodium-water reaction simulation instruction, and determining a target sodium-water reaction model based on a reaction type identifier in the sodium-water reaction simulation instruction, wherein the target sodium-water reaction model is the tiny sodium-water reaction model or the large sodium-water reaction model; Simulating a sodium-water reaction accident based on the target sodium-water reaction model to obtain a sodium-water reaction simulation result; The sodium-water reaction simulation results are input into a full-heap simulation model to obtain full-heap accident response results.

2. The sodium-water reaction accident simulation method for a sodium-cooled fast reactor according to claim 1, characterized in that: The small sodium-water reaction model is a reaction model corresponding to a small leakage. A small leakage is when the hydrogen concentration in the sodium gas in the secondary circuit exceeds 0.17×10 -6 , and / or, the hydrogen concentration in the argon gas exceeds 0.07×10 -2 Leakage situation at the time; The large sodium water reaction model is a reaction model corresponding to a large leakage. A large leakage is a leakage when any two of the following three situations occur: the argon pressure in the buffer tank in the secondary circuit exceeds 0.34MPa or is lower than 0.26MPa, the sodium liquid level in the buffer tank reaches an increase of 20cm or an increase of 5cm / s, and the difference in sodium flow at the inlet and outlet of the steam generator reaches 20% of the normal flow.

3. The sodium-water reaction accident simulation method for a sodium-cooled fast reactor according to claim 1, characterized in that: The tiny sodium-water reaction model is: ； ； ； In the formula, is a one-way reaction identifier; is a reversible reaction identifier.

4. The sodium-water reaction accident simulation method for a sodium-cooled fast reactor according to claim 1, characterized in that: When the target sodium-water reaction model is a tiny sodium-water reaction model, the simulation based on the target sodium-water reaction model to obtain a sodium-water reaction simulation result includes: Obtaining a first water leakage rate; Determine the hydrogen ion yield based on the first water leakage rate and the tiny sodium-water reaction model; Among them, the first water leakage rate is regarded as a complete response.

5. The sodium-water reaction accident simulation method for a sodium-cooled fast reactor according to claim 1, characterized in that: The sodium water reaction model includes a reaction heat generation calculation model, a spherical bubble growth calculation model and a columnar bubble growth model; The reaction heat generation calculation model is: ； ； The calculation model of spherical bubble growth is: ； ； ； ； ； ； ； ； The cylindrical bubble growth model is: ； ； ； ； ； ； ； In the formula, Produce heat for the reaction; The chemical heat of reaction is to produce - mole of hydrogen; is the amount of hydrogen produced; is the amount of leaked water generated; is the ratio of hydrogen production to the amount of water leaked; is the internal temperature of the bubble; For time; is the initial temperature of the hydrogen produced in the reaction; It is a parameter to characterize the physical properties of hydrogen; is the bubble volume; The quality of the leaked water; is the pressure inside the bubble; is the bubble radius; is the radial velocity of liquid sodium due to bubble growth and extrusion; is the liquid sodium pressure at the sodium-hydrogen interface; , are the flow rates of liquid sodium on the left and right sides of the bubble respectively; , is the growth rate of the left and right sides of the bubble; , is the pressure of liquid sodium on the left and right sides of the bubble; is the drag coefficient caused by viscosity; is the time step; is the characteristic line value on the left side of the bubble; is the characteristic line value on the right side of the bubble; is the characteristic length; is the growth rate of the bubble; is the length of the bubble.

6. The sodium-water reaction accident simulation method for a sodium-cooled fast reactor according to claim 1, characterized in that: When the target sodium-water reaction model is a large sodium-water reaction model, simulation is performed based on the target sodium-water reaction model to obtain a sodium-water reaction simulation result, including: Obtain the pressure difference in the third-loop steam generator in the core area of ​​the large sodium water reaction of the second loop; determining a second water leakage rate based on the pressure difference; Obtain the secondary circuit temperature and secondary circuit pressure at both ends of the steam generator pipe section specified by the rupture; The reaction heat release, the flow change of the sodium circuit during the reaction, the reactant consumption rate, the reaction product composition, the reaction product generation rate and the pressure fluctuation of the sodium circuit in the initial stage of the reaction are determined based on the secondary circuit temperature, the secondary circuit pressure, the second water leakage rate and the large sodium-water reaction model.

7. The sodium-water reaction accident simulation method for a sodium-cooled fast reactor according to claim 6, characterized in that: The determining a second water leakage rate based on the pressure difference comprises: Determining whether the pressure difference is greater than a pressure difference threshold; When the pressure difference is greater than the pressure difference threshold, determining a second water leakage rate based on a critical leakage flow calculation method; When the pressure difference is less than or equal to the pressure difference threshold, a second water leakage rate is determined based on a preset leakage calculation model.

8. The sodium-water reaction accident simulation method for a sodium-cooled fast reactor according to claim 1, characterized in that: The step of inputting the sodium-water reaction simulation result into the full-stack simulation model to obtain the full-stack accident response result includes: Step 1: Obtain simulation control variables; Step 2, obtaining the reactor operating conditions at the last time step or the initial moment; Step 3: obtaining a reactor SimTherm simulation model, and inputting the simulation control variables, the reactor operating conditions at the previous time step or the initial moment, and the sodium-water reaction simulation results into the reactor SimTherm simulation model for coupling calculation to obtain a full-reactor accident response result; Step 4: Determine whether a simulation pause signal is received and whether a preset simulation time has been reached; Step 5: If the simulation pause signal is received or the preset simulation time is reached, then the simulation is ended; if the simulation pause signal is not received and the preset simulation time is not reached, then the process returns to step 2.

9. The sodium-water reaction accident simulation method for a sodium-cooled fast reactor according to claim 1, characterized in that: The sodium-water reaction accident simulation method for the sodium-cooled fast reactor also includes: Sodium-water reaction accident reference data is obtained, and the accuracy of the sodium-water reaction model is verified based on the sodium-water reaction accident reference data and the full-reactor accident response result.

10. A sodium-water reaction accident simulation system for a sodium-cooled fast reactor, characterized in that: include: A sodium-water reaction model construction unit, used to construct a sodium-water reaction model, wherein the sodium-water reaction model includes a small sodium-water reaction model and a large sodium-water reaction model; a sodium-water reaction model selection unit, configured to obtain a sodium-water reaction simulation instruction, and determine a target sodium-water reaction model based on a reaction type identifier in the sodium-water reaction simulation instruction, wherein the target sodium-water reaction model is a small sodium-water reaction model or a large sodium-water reaction model; A sodium-water reaction simulation unit, used to perform simulation based on the target sodium-water reaction model to obtain a sodium-water reaction simulation result; The whole-stack accident simulation unit is used to input the sodium-water reaction simulation result into the whole-stack simulation model to obtain the whole-stack accident response result.

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