Irradiation sample tube plug stability confirmation method and electronic device

Abstract

The present application relates to a kind of irradiation sample tube plug stability confirmation method and electronic equipment.The method includes: based on preset estimation model, the node model of primary loop and reactor pool in nuclear power unit is generated;According to the input card corresponding to node model is generated;The initial operating condition of node model and the water level parameter of reactor pool in node model are set;The flow parameter of reactor core inner channel in node model is set as rated value, and the resistance coefficient parameter in node model is adjusted, so that the pressure difference value of each node in node model is corresponding target value;Nuclear power unit corresponding to water filling working mode is generated according to node model, so that injection flow parameter gradually increases to target set value within preset time;The node pressure difference of second preset node minus first preset node is obtained, to obtain the stability confirmation result of irradiation sample tube plug.The present application is implemented when filling water in nuclear power unit, the stability analysis of irradiation sample tube plug is guaranteed, and the safe operation of reactor is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear power, more particularly, to a method for confirming stability of an irradiation sample tube plug and an electronic device. BACKGROUND

[0002] After the large cover of the pressure vessel in the down-regulation stage of the unit, the primary loop and the reactor pool are filled with water for refueling, and the reactor pool cooling treatment system pump (PTR002PO) can be used to fill the reactor pool through the component pool. Alternatively, a water filling method with a flow rate greater than that of the PTR002PO can be used, such as a low-pressure safety injection pump, a primary loop hot section, and a cold section injection through a safety injection line.

[0003] The change in mechanical properties of the pressure vessel material after irradiation is tested to ensure that the pressure vessel will not be brittle and broken, such as Figure 3 As shown in the figure, one irradiation sample holder is arranged on the outside of each of the three heat shields of the pressure vessel, and each sample holder has two holes for placing two irradiation sample supervision tubes, and the tubes are filled with samples of reactor materials and welding materials. The samples can be taken out through the corresponding holes of the basket flange by means of special tools without the need to disassemble the lower core support structure. The irradiation sample plug corresponding to each hole is placed on the core basket.

[0004] Under normal operating conditions of the reactor, the irradiation sample tube plug is pressed by the large cover of the pressure vessel and the upper in-core component, so it will not be washed away. Under the refueling shutdown condition, the reactor large cover and the upper in-core component are lifted away, and the sample tube plug is only placed on the hole seat by gravity. In addition to flowing to the outlet of the core, the coolant in the active zone of the core also flows to the upper reactor pool, and the increased flow rate may wash away the irradiation sample plug placed on the core basket. If the irradiation sample plug is washed away from the hole seat, it may cause damage to the basket during the process of reinstalling the upper in-core component at the end of refueling, or it may be washed out of the hole seat and fall into the upper core, causing damage to the fuel assembly. In addition, after the sample tube plug is washed out, the bypass flow of the core increases, affecting the heat transfer of the core.

[0005] Under the refueling shutdown mode, the stability of the irradiation sample tube plug must be ensured during the process of filling the primary loop with water, and there is currently no quantitative and rigorous analysis method. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a method for confirming stability of an irradiation sample tube plug and an electronic device to solve the above technical defects of the prior art.

[0007] The technical solution adopted by the present application to solve the technical problem is: a method for confirming stability of an irradiation sample tube plug is constructed, which is applied to the process of filling the primary loop with water during refueling shutdown of a nuclear power unit, and the method comprises the following steps:

[0008] S1, generating a node model of a primary loop and a reactor pool in a nuclear power unit based on a preset estimation model, wherein a node corresponding to the reactor pool in the nuclear power unit is a first preset node, and a node corresponding to an irradiation sample tube plug in the nuclear power unit is a second preset node;

[0009] S2, generating an input card corresponding to a node according to the node model; wherein the input card comprises a node parameter corresponding to the node in the node model;

[0010] S3, setting an initial operating condition of the node model corresponding to the nuclear power unit, and setting a water level parameter of the reactor pool in the node model corresponding to the nuclear power unit as a preset value;

[0011] S4, setting a flow parameter of a reactor core internal flow passage in the node model as a rated value, and adjusting a resistance coefficient parameter of the nuclear power unit in the node model, so that a pressure difference value of each node in the node model is a corresponding target value respectively;

[0012] S5, generating a water filling operation mode corresponding to the nuclear power unit according to the node model, and setting an injection flow parameter in the node model to gradually increase to a target set value within a preset time;

[0013] S6, obtaining a node pressure difference of the second preset node minus the first preset node according to the node model, to obtain a stability confirmation result of the irradiation sample tube plug according to the node pressure difference.

[0014] Preferably, in the irradiation sample tube plug stability confirmation method, in the step S1, the node model of the primary loop and the reactor pool in the nuclear power unit is generated based on a preset estimation model, comprising:

[0015] Based on the RELAP (Reactor Excursion and Leak Analysis Program) optimal estimation model of a light water reactor, the primary loop system and the reactor pool of the pressurized water reactor unit are modeled to obtain the node model.

[0016] Preferably, in the irradiation sample tube plug stability confirmation method, in the step S2,

[0017] When the node of the node model corresponds to a flow passage assembly, the node parameter comprises one or more of a flow passage area, a length, an inclination angle, a height change, a wall roughness, a hydraulic diameter, a resistance coefficient when flowing forward and flowing backward, an initial flow, and a flow rate of the flow passage assembly;

[0018] When the node of the node model corresponds to a thermal component, the node parameter comprises one or more of a material of the thermal component and its thermal conductivity and volumetric heat capacity, a heat transfer area, a source term, and a heat sink.

[0019] Preferably, in the irradiation sample tube plug stability confirmation method, in the step S3, the setting the node model to correspond to the initial operating condition of the nuclear power unit comprises:

[0020] Setting the node model to correspond to a loop opening operating condition of the nuclear power unit when operating in a single RRA pump operation mode.

[0021] Preferably, in the irradiation sample tube plug stability confirmation method, in the step S4, the setting the flow parameter of the reactor core internal flow passage in the node model to a rated value comprises:

[0022] Calculating a rated flow of the reactor at zero power based on the node model, and setting the rated flow as the rated value of the flow parameter of the reactor core internal flow passage in the node model.

[0023] Preferably, in the irradiation sample tube plug stability confirmation method, in the step S5, further comprising:

[0024] Obtaining the preset time according to the pump starting time and the valve opening time of the nuclear power unit.

[0025] Preferably, in the irradiation sample tube plug stability confirmation method, the time is 5s.

[0026] Preferably, in the irradiation sample tube plug stability confirmation method, in the step S6, the obtaining the stability confirmation result of the irradiation sample tube plug according to the node differential pressure comprises:

[0027] Obtaining a critical differential pressure of the upper and lower cross sections of the irradiation sample tube plug on the core basket hole seat in a stable state; comparing the node differential pressure with the critical differential pressure, and determining that the irradiation sample tube plug is in a stable state when the node differential pressure is less than or equal to the critical differential pressure, otherwise determining that the irradiation sample tube plug is in an unstable state.

[0028] Preferably, in the irradiation sample tube plug stability confirmation method, in the step S5, the nuclear power unit corresponds to a water charging operating mode, comprising:

[0029] A water charging operating mode of charging water through a high-pressure emergency injection system of the nuclear power unit; or

[0030] A water charging operating mode of charging water through a low-pressure emergency injection system of the nuclear power unit.

[0031] In addition, the present application also constructs an electronic device, comprising a memory and a processor;

[0032] The memory is used for storing a computer program;

[0033] The processor is configured to execute the computer program to implement the method as described above.

[0034] The irradiation sample tube plug stability confirmation method and the electronic device of the present application have the following beneficial effects: the stability of the irradiation sample tube plug under a specific water filling mode can be analyzed to ensure the safe operation of the reactor under the corresponding water filling mode. BRIEF DESCRIPTION OF DRAWINGS

[0035] The present application will be further described below in conjunction with the accompanying drawings and examples, wherein:

[0036] Figure 1 is a program flow chart of an embodiment of the irradiation sample tube plug stability confirmation method of the present application;

[0037] Figure 2 is a structural schematic diagram of an embodiment of a node model in the present application;

[0038] Figure 3 is a structural schematic diagram of an irradiation sample supervision tube installation structure in a nuclear power unit. DETAILED DESCRIPTION

[0039] In order to have a clearer understanding of the technical features, objectives and effects of the present application, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0040] As shown in Figure 1 , an embodiment of the irradiation sample tube plug stability confirmation method of the present application is disclosed. The embodiment is applied to the refueling shutdown water filling process of a nuclear power unit. In the embodiment, the irradiation sample tube plug stability confirmation method comprises the following steps: Figure 1In an embodiment of a method for confirming the stability of an irradiated sample tube plug of the present invention, the method includes the following steps: S1, based on a preset estimation model, generating a node model of a primary circuit and a reactor pool in a nuclear power unit, wherein the node corresponding to the reactor pool in the nuclear power unit is a first preset node, and the node corresponding to the irradiated sample tube plug in the nuclear power unit is a second preset node; S2, generating an input card corresponding to the node according to the node model; wherein the input card includes the node parameters corresponding to the node in the node model; S3, setting the node model to the initial operating condition of the nuclear power unit, and setting the node model of the nuclear power unit in the node model. The water level parameter of the reactor pool is a preset value; S4, setting the flow parameter of the flow channel in the reactor core in the node model to the rated value, and adjusting the resistance coefficient parameter of the nuclear power unit in the node model so that the pressure difference value of each node in the node model is the corresponding target value; S5, generating the corresponding water filling working mode of the nuclear power unit according to the node model, and setting the injection flow parameter in the node model to gradually increase to the target set value within a preset time; S6, obtaining the node pressure difference obtained by subtracting the first preset node from the second preset node according to the node model, so as to obtain the stability confirmation result of the irradiated sample tube plug according to the node pressure difference.

[0041] Based on the above step S1, a node model of the primary loop system and the reactor pool in the nuclear power unit can be established based on the best estimation procedure commonly used in the field of nuclear power. In the process of establishing the node model, corresponding nodes can be established based on the purpose and connection relationship of each component in the nuclear power unit. The setting of the node can be implemented as a single component or a set of components as needed. For example, a single component can be set to correspond to a node in the node model, or a functional module containing multiple single components can be set to correspond to a node in the node model. In a specific embodiment, a primary loop may include a pressure vessel, a hot pipe section, a steam generator, a pressurizer, a primary side part of the steam generator, a valve, a main pump and a cold pipe section. The reactor pool is the reactor pool of the unit, which is used to reflect the actual situation of the unit. As Figure 2 The figure below shows a schematic diagram of the functional modules of a nuclear power plant, along with a partial example of a node model diagram for a specific embodiment. Node number 150 corresponds to the node corresponding to the reactor pool in the nuclear power plant and can be understood as the first preset node. Node numbers 1001 / 1002 correspond to the nodes where the irradiated sample plugs are located and can be understood as the second preset node. Node numbers can also be generated for other components. For example, each heat pipe segment can be segmented and node numbers generated for each component or connection relationship. This is not limited in this embodiment.

[0042] Based on step S2, the corresponding input card is generated for part or all of the nodes in the node model, which can be understood as a function module in the software program. When the software program is running, the function module is called as needed. In the embodiment, the node parameters corresponding to each node in the node model are set by setting the input card, so that when the calculation is performed based on the node model, the input card is called as needed to obtain the corresponding working parameters.

[0043] Based on step S3, in the specific calculation, the state of the node model is set to correspond to the initial working condition of the nuclear power unit. It can be understood that the initial working condition is the working condition before the nuclear power unit is filled with water. The same working condition or different working conditions can be selected based on different working scenarios. At the same time, the water level parameter of the nuclear power unit reactor pool in the node model is set according to the actual water level in the nuclear power unit reactor pool. For example, when the water level of the top cover flange of the nuclear power unit reactor pool is 10.5 meters, the water level parameter of the nuclear power unit reactor pool in the node model is set to 10.5 meters.

[0044] Based on step S4, the flow parameter corresponding to the reactor core internal flow passage in the node model is set to a rated value and remains unchanged. By adjusting the resistance coefficient parameter of the nuclear power unit in the node model, it is confirmed whether the pressure difference value of each node in the node model meets the requirements, for example, whether it is within the preset requirement range, and the adjustment is stopped when the pressure difference value is within the preset requirement range.

[0045] Based on step S5, when the resistance coefficient parameter of the nuclear power unit in the node model is fixed, the working mode of the node model can be set according to the actual working condition of the nuclear power unit, so that the working mode of the node model is the filling mode corresponding to the required nuclear power unit, and the injection flow parameter of the node model is gradually increased to the target set value within a preset time. In an embodiment, but not limited to, the preset time is obtained according to the pump starting time and valve opening time of the nuclear power unit. In a specific embodiment, the preset time can be set to 5 seconds, that is, by setting the preset time, the injection flow parameter in the node model is linearly increased to the set injection flow within 5 seconds, which corresponds to the target set value.

[0046] Based on step S6, the node pressure difference obtained by subtracting the first preset node from the second preset node in the node model is obtained. Through the node pressure difference, it can be determined whether the irradiated sample tube plug has a stability problem at this time to obtain a stability confirmation result of the irradiated sample tube plug. That is, by obtaining the process, the pressure difference of the upper and lower sections of the irradiated sample tube plug in the coolant under different filling modes can be analyzed, and then the stability of the irradiated sample tube plug under different filling modes is obtained, to ensure the safe operation of the reactor under the corresponding filling mode.

[0047] Optionally, in the step S1, the node model of the primary loop and the reactor pool of the nuclear power unit is generated based on a preset estimation model, including: based on the best estimation model RELAP of light water reactor, the primary loop system and the reactor pool of the pressurized water reactor unit are modeled integrally to obtain the node model. Specifically, the node model is established by using the best estimation model RELAP of light water reactor commonly used in the field of nuclear power.

[0048] Optionally, in the step S2, when the input card corresponding to the node is generated, when the node of the node model corresponds to the flow-through component, the node parameters include one or more of the flow-through area, length, inclination angle, height variation, wall roughness, hydraulic diameter, resistance coefficient when forward flow and reverse flow, initial flow and flow rate of the flow-through component; when the node of the node model corresponds to the thermal component, the node parameters include one or more of the material and its thermal conductivity and volumetric heat capacity, heat transfer area, source term, and heat sink of the thermal component. Specifically, when the input card in the node model is set based on the design parameters and operating parameters of the system and equipment in the nuclear power unit. Wherein, the design parameters and operating parameters of the system and equipment can be refined to specific components or components, and different parameters are selected as design input cards based on the type or function of the components or components.

[0049] Optionally, in the step S3, the initial operating condition of the node model corresponding to the nuclear power unit is set, including: setting the initial operating condition of the node model corresponding to the nuclear power unit working in the primary loop open operating condition when a single RRA pump is running. Specifically, in the process of calculation based on the node model, the initial state of the node model is first set to correspond to the primary loop open operating condition when the nuclear power unit works in a single RRA pump running, and the subsequent parameter setting is carried out under this operating condition.

[0050] Optionally, in the step S4, the flow parameter of the flow passage in the reactor core in the node model is set to the rated value, including: calculating the rated flow of the reactor at zero power based on the node model, and taking the rated flow as the rated value of the flow parameter of the flow passage in the reactor core in the node model. Specifically, in actual application, the resistance coefficient of the flow passage in the reactor core has a great influence on the final calculation result of the node model. Therefore, a method with high accuracy is needed to calculate the resistance coefficient. In the calculation process, the rated flow of the reactor at zero power is calculated by the established node model, and the rated flow is taken as the rated value of the flow parameter of the flow passage in the reactor core in the node model.

[0051] Optionally, in the step S6, the obtaining the stability confirmation result of the irradiation sample tube plug according to the node pressure difference comprises: obtaining an upper and lower cross-section critical pressure difference of the irradiation sample tube plug on the core basket hole seat; comparing the node pressure difference with the critical pressure difference, when the node pressure difference is less than or equal to the critical pressure difference, determining that the irradiation sample tube plug is in a stable state, otherwise determining that the irradiation sample tube plug is in an unstable state. Specifically, the upper and lower cross-section critical pressure difference ΔPcr of the tube plug on the core basket hole seat can be obtained based on stress analysis of the irradiation sample tube plug. cr . Wherein, in the refueling cold shutdown condition, the reactor pressure vessel top cover and the upper in-core structure are lifted away, and the sample tube plug is placed on the hole seat only by gravity. That is, it can be understood that the force of the irradiation sample plug in the refueling cold shutdown condition is mainly the gravity G, the buoyancy F b and the pressure caused by the different pressure differences of the upper and lower ends of the tube plug during the coolant transmission process. If the tube plug is to be pushed away from the hole seat on the basket, the upward pressure formed by the pressure difference of the upper and lower ends of the tube plug must overcome the gravity and the buoyancy. Then the critical pressure difference of the hole seat for maintaining the stability of the irradiation sample plug is:

[0052] ;

[0053] Wherein, S is the area of the end face of the tube plug. In the stability analysis process, if ΔP calculated by the overall model of the water filling mode is less than the critical stability pressure difference ΔPcr of the hole seat, the irradiation sample tube plug maintains stability during the water filling process; otherwise, the irradiation sample tube plug will be pushed, and the irradiation sample tube plug has stability problems.

[0054] Optionally, in the step S5, the corresponding water filling working mode of the nuclear power unit comprises: a water filling working mode of filling water through a high-pressure injection system of the nuclear power unit; or a water filling working mode of filling water through a low-pressure injection system of the nuclear power unit. Specifically, according to the actual working condition of the nuclear power unit, the high-pressure injection system and the low-pressure injection system can both realize the injection of coolant with certain pressure and flow through the injection nozzle into the primary loop system and the reactor pool. Wherein, the low-pressure injection system can include low-pressure injection cold section injection, low-pressure injection hot section injection, etc.

[0055] In practical application, when the nuclear power unit adopts a high-pressure injection pump or a low-pressure injection pump for primary loop hot section injection or cold section injection, the irradiation sample tube plug stability analysis method can be used to select a fast water filling mode under the premise of ensuring the stability of the reactor components, shorten the key path of overhaul, and improve the economy of the unit.

[0056] In addition, the electronic device of the present application can further include a memory and a processor; the memory is used to store a computer program; the processor is used to execute the computer program to realize the above method. Specifically, according to the embodiments of the present application, the processes described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments of the present application include a computer program product comprising a computer program carried on a computer readable medium, the computer program comprising program codes for executing the method shown in the flowchart. In such embodiments, the computer program can be downloaded and installed by the electronic device and executed to perform the above functions defined in the method of the embodiments of the present application. The electronic device in the present application can be a notebook, a desktop, a tablet computer, a smart phone, etc. terminal, or a server.

[0057] It can be understood that the above embodiments only express the preferred embodiments of the present application, which are described in detail and specifically, but cannot be understood as the limitation of the patent scope of the present application; it should be pointed out that for those skilled in the art, the above technical features can be freely combined without departing from the concept of the present application, and some modifications and improvements can be made, which all belong to the protection scope of the present application; therefore, any equivalent transformation and modification within the scope of the claims of the present application should belong to the scope of the claims of the present application.

Claims

1. A method for confirming the stability of an irradiated sample tube plug, characterized in that: Applied to the process of water filling during the shutdown of a nuclear power unit for refueling, the method comprises the following steps: S1. Generate a node model of the primary circuit and the reactor pool in a nuclear power unit based on a preset estimation model, wherein the node corresponding to the reactor pool in the nuclear power unit is a first preset node, and the node corresponding to the irradiated sample tube plug in the nuclear power unit is a second preset node; S2. Generate an input card corresponding to a node according to the node model, wherein the input card includes node parameters corresponding to the node in the node model; S3, setting the node model to correspond to the initial operating condition of the nuclear power unit, and setting the water level parameter of the reactor pool of the nuclear power unit in the node model to a preset value; S4. Setting the flow parameters of the flow channel in the reactor core in the node model to rated values, and adjusting the resistance coefficient parameters of the nuclear power unit in the node model so that the pressure difference values ​​of the nodes in the node model are respectively corresponding to the target values; S5. Generate a water filling operation mode corresponding to the nuclear power unit according to the node model, and set the injection flow parameter in the node model to gradually increase to a target set value within a preset time; S6. Obtaining, according to the node model, a node pressure difference obtained by subtracting the first preset node from the second preset node, and obtaining a stability confirmation result of the irradiated sample tube plug according to the node pressure difference; In step S2, When the node of the node model corresponds to a flow component, the node parameters include one or more of the flow area, length, inclination angle, height change, wall roughness, hydraulic diameter, resistance coefficient during forward flow and reverse flow, initial flow rate, and flow velocity of the flow component; When a node in the node model corresponds to a thermal component, the node parameters include the material of the thermal component and one or more of its thermal conductivity and volumetric heat capacity, heat transfer area, source term, and heat sink.

2. The method for confirming the stability of an irradiated sample tube plug according to claim 1, wherein: In step S1, generating a node model of the primary circuit and the reactor pool in the nuclear power unit based on a preset estimation model includes: Based on the light water reactor best estimate model RELAP, the primary loop system and reactor pool of the pressurized water reactor unit are modeled as a whole to obtain the node model.

3. The method for confirming the stability of irradiated sample tube plugs according to claim 1, characterized in that: In step S3, setting the node model to correspond to the initial operating condition of the nuclear power unit includes: The node model is set to correspond to the single-loop open condition of the nuclear power unit operating with a single RRA pump.

4. The method for confirming the stability of an irradiated sample tube plug according to claim 1, wherein: In step S4, setting the flow parameters of the flow channel in the reactor core in the node model to rated values ​​includes: The rated flow rate of the reactor at zero power is calculated based on the node model, and the rated flow rate is used as the rated value of the flow parameter of the flow channel in the reactor core in the node model.

5. The method for confirming the stability of irradiated sample tube plugs according to claim 1, characterized in that: In the step S5, it further includes: The preset time is obtained according to the pump starting time and valve opening time of the nuclear power unit.

6. The method for confirming the stability of an irradiated sample tube plug according to claim 5, wherein: The preset time is 5s.

7. The method for confirming the stability of an irradiated sample tube plug according to claim 1, wherein: In step S6, obtaining the stability confirmation result of the irradiated sample tube plug according to the node pressure difference includes: Obtaining a critical pressure difference between the upper and lower sections of the irradiated sample tube plug that is stable on the core hanging basket hole seat; comparing the node pressure difference with the critical pressure difference; and determining that the irradiated sample tube plug is in a stable state when the node pressure difference is less than or equal to the critical pressure difference; otherwise, determining that the irradiated sample tube plug is in an unstable state.

8. The method for confirming the stability of an irradiated sample tube plug according to claim 1, wherein: In step S5, the nuclear power unit corresponds to a water filling operation mode, including: A water filling operation mode in which water is filled through the high-pressure safety injection system of the nuclear power unit; or A water filling working mode is performed by filling water through the low-pressure safety injection system of the nuclear power unit.

9. An electronic device, characterized in that: including memory and processor; The memory is used to store computer programs; The processor is configured to execute the computer program to implement the method according to any one of claims 1 to 8.

Images