Method for confirming stability of irradiation sample tube plug and electronic equipment

Abstract

The invention relates to an irradiation sample tube plug stability confirmation method and electronic equipment. The method comprises the steps of generating node models of a loop and a reactor pool in a nuclear power unit based on a preset estimation model; generating a corresponding input card according to the node model; setting an initial working condition of the node model and a reactor pool water level parameter in the node model; setting a flow parameter of a flow channel in a reactor core in the node model as a rated value, and adjusting a resistance coefficient parameter in the node model, so that a pressure difference value of each node in the node model is a corresponding target value; generating a water filling working mode corresponding to the nuclear power unit according to the node model, so that the injection flow parameter is gradually increased to a target set value within a preset time; and obtaining a node pressure difference obtained by subtracting the first preset node from the second preset node so as to obtain a stability confirmation result of the irradiation sample tube plug. When the nuclear power unit is filled with water, the stability of the irradiation sample tube plug is analyzed, and safe operation of a reactor is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power technology, and more specifically to a method for confirming the stability of an irradiated sample tube plug and electronic equipment. Background Art

[0002] After opening the main cover of the pressure vessel during the unit's downlink phase, the primary circuit and the reactor pool are filled with water for material replacement. The reactor pool cooling treatment system pump (PTR002PO) can be used to fill the reactor pool with water through the component pool. Alternatively, a filling method with a flow rate greater than PTR002PO can be used, such as using a low-pressure injection pump to inject into the hot and cold sections of the primary circuit through the injection pipeline.

[0003] Test the changes in mechanical properties of pressure vessel materials after being irradiated to ensure that the pressure vessel will not fracture brittlely, such as Figure 3 As shown in the figure, an irradiation sample rack is installed on the outside of each of the three heat shields of the pressure vessel. Each sample rack has two holes, which can hold two irradiation sample monitoring tubes, and the tubes are filled with samples of reactor materials and welding materials. The samples can be taken out through the corresponding holes on the hanging basket flange with the help of special tools, without disassembling the lower core support structure. The irradiation sample plug corresponding to each hole is placed on the core hanging basket.

[0004] Under normal reactor operation, the irradiated sample plug will not be dislodged because it is pressed by the pressure vessel cover and upper internal components. Under refueling shutdown, the reactor cover and upper internal components are lifted off, and the sample plug is placed on the hole seat by gravity. The coolant passing through the core active area flows to the core outlet as well as the upper reactor pool. The increased flow rate may impact the irradiated sample plug placed on the core basket. If the irradiated sample plug is separated from the hole seat, it may be squeezed by the upper components during the process of reinstalling the upper internal components after refueling, causing damage to the basket. It may also break out of the hole seat and fall into the upper part of the core, causing damage to the fuel assembly. In addition, after the sample plug is dislodged, the core bypass flow rate increases, affecting the heat transfer of the core.

[0005] In the refueling shutdown mode, the stability of the irradiated sample tube plug must be ensured during the water filling process into the primary circuit. Currently, there is no quantitative and rigorous analysis method. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method and electronic equipment for confirming the stability of an irradiated sample tube plug in view of the above-mentioned technical defects of the prior art.

[0007] The technical solution adopted by the present invention to solve the technical problem is: construct a method for confirming the stability of an irradiated sample tube plug, which is applied to the process of stopping the reactor for refueling and filling water in a nuclear power unit. The method comprises the following steps:

[0008] S1. Based on a preset estimation model, a node model of a primary circuit and a reactor pool in a nuclear power unit is generated, 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;

[0009] 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;

[0010] 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;

[0011] 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;

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

[0013] S6. Obtaining a node pressure difference obtained by subtracting the first preset node from the second preset node according to the node model, so as to obtain a stability confirmation result of the irradiated sample tube plug according to the node pressure difference.

[0014] Preferably, in the method for confirming the stability of the irradiated sample tube plug described in the present invention, in the step S1, generating the node model of the primary circuit and the reactor pool in the nuclear power unit based on the preset estimation model includes:

[0015] Based on the light water reactor optimal estimate model RELAP, the primary loop system and the reactor pool of the pressurized water reactor unit are modeled as a whole to obtain the node model.

[0016] Preferably, in the method for confirming the stability of the irradiated sample tube plug of the present invention, in step S2,

[0017] When the node of the node model corresponds to a flow component, the node parameter includes 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;

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

[0019] Preferably, in the method for confirming the stability of the irradiated sample tube plug of the present invention, in step S3, setting the node model to correspond to the initial operating condition of the nuclear power unit includes:

[0020] The node model is set to correspond to the nuclear power unit operating in a single-loop open condition with a single RRA pump.

[0021] Preferably, in the method for confirming the stability of an irradiated sample tube plug of the present invention, in step S4, setting the flow parameter of the flow channel in the reactor core in the node model to a rated value comprises:

[0022] 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.

[0023] Preferably, in the method for confirming the stability of the irradiated sample tube plug of the present invention, in the step S5, it further includes:

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

[0025] Preferably, in the method for confirming the stability of an irradiated sample tube plug described in the present invention, the time is 5 s.

[0026] Preferably, in the method for confirming the stability of the irradiated sample tube plug of the present invention, in step S6, obtaining the stability confirmation result of the irradiated sample tube plug according to the node pressure difference includes:

[0027] Obtain the critical pressure difference of the upper and lower sections of the irradiated sample tube plug that is stable on the core hanging basket hole seat; compare the node pressure difference with the critical pressure difference, and when the node pressure difference is less than or equal to the critical pressure difference, determine that the irradiated sample tube plug is in a stable state; otherwise, determine that the irradiated sample tube plug is in an unstable state.

[0028] Preferably, in the method for confirming the stability of the irradiated sample tube plug of the present invention, in the step S5, the nuclear power unit corresponds to the water filling working mode, including:

[0029] A water filling operation mode in which water is filled through the high pressure safety injection system of the nuclear power unit; or

[0030] A water filling working mode is performed by filling water through the low-pressure safety injection system of the nuclear power unit.

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

[0032] The memory is used to store computer programs;

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

[0034] The method and electronic equipment for confirming the stability of an irradiated sample tube plug according to the present invention have the following beneficial effects: stability analysis of the irradiated sample tube plug can be realized under a specific water filling mode to ensure the safe operation of the reactor under the corresponding water filling mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0036] Figure 1 It is a flowchart of a method for confirming the stability of an irradiated sample tube plug according to an embodiment of the present invention;

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

[0038] Figure 3 It is a schematic diagram of the installation structure of the irradiation sample monitoring tube in a nuclear power unit. DETAILED DESCRIPTION

[0039] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0040] like Figure 1 As shown, an embodiment of the present invention is disclosed for a method for confirming the stability of an irradiated sample tube plug. This embodiment is applied to the process of stopping the reactor for water filling during fuel replacement in a nuclear power unit. 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 loop 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 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 node model to correspond to the initial operating condition of the nuclear power unit. 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 nuclear power field. 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 a 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 As shown, it is a schematic diagram of the functional modules of a nuclear power unit, and a local example of a node model schematic diagram of a specific embodiment is given. Among them, the node number 150 corresponds to the node corresponding to the reactor pool in the nuclear power unit, which can be understood as the first preset node, and the node code 1001 / 1002 is the node corresponding to the location of the irradiated sample plug, which can be understood as the second preset node. Corresponding node numbers can also be generated for other components. For example, each heat pipe segment is divided into components, and a node number is generated corresponding to each component or connection relationship. It is not limited in this embodiment.

[0042] Based on step S2, corresponding input cards are generated for some or all of the nodes in the node model. The input cards can be understood as function modules in the software program. When the software program is running, the function modules are called as needed. In this embodiment, the node parameters corresponding to each node in the node model are set by setting the input cards, so that when calculating based on the node model, the input cards are 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 operating condition of the nuclear power unit. It can be understood that the initial operating condition is the operating condition before the nuclear power unit is filled with water. The selection of the operating condition can select the same operating condition or different operating conditions based on different working scenarios. At the same time, the water level parameters of the reactor pool of the nuclear power unit in the node model are set according to the actual water level height in the reactor pool of the nuclear power unit. For example, when the water level of the top cover flange surface in the reactor pool of the nuclear power unit is 10.5 meters, the water level parameters of the reactor pool of the nuclear power unit in the node model are set to 10.5 meters.

[0044] Based on step S4, the flow parameters corresponding to the flow channel in the reactor core in the node model are set to the rated values ​​and remain unchanged. By adjusting the resistance coefficient parameters of the nuclear power unit in the node model, it is confirmed during the adjustment process 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 required water filling mode corresponding to the nuclear power unit, and the injection flow parameter of the node model is set to gradually increase to the target setting value within the preset time. In one embodiment, it includes but is not limited to obtaining the preset time according to the pump start 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, that is, the corresponding target setting value within 5 seconds.

[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, and the node pressure difference can be used to determine whether the irradiated sample plug has a stability problem at this time to obtain the stability confirmation result of the irradiated sample plug. That is, through this process, the pressure difference between the upper and lower sections of the irradiated sample plug in the coolant under different water filling methods can be analyzed, and then the stability of the irradiated sample plug under different water filling methods can be obtained to ensure the safe operation of the reactor under the corresponding water filling method.

[0047] Optionally, in step S1, generating a node model of a primary circuit and a reactor pool in a nuclear power unit based on a preset estimation model includes: based on a light water reactor optimal estimation model RELAP, integrally modeling a primary circuit system and a reactor pool of a pressurized water reactor unit to obtain the node model. Specifically, the node model is established using the light water reactor optimal estimation model RELAP commonly used in the nuclear power field.

[0048] Optionally, in step S2, when generating an input card corresponding to a node, 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 the node in the node model corresponds to a thermal component, the node parameters include one or more of the material of the thermal component and its thermal conductivity and volume heat capacity, heat transfer area, source term, and heat sink. Specifically, 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. Among them, the design parameters and operating parameters of the system and equipment can be refined to specific components or assemblies, and different parameters are selected as design input cards based on the type or function of the component or assembly.

[0049] Optionally, in step S3, setting the node model to correspond to the initial operating condition of the nuclear power unit includes: setting the node model to correspond to the operating condition of the nuclear power unit operating in a single RRA pump with a single circuit open. Specifically, in the process of calculating based on the node model, the initial state of the node model is first set to correspond to the operating condition of the nuclear power unit operating in a single RRA pump with a single circuit open, and the subsequent parameter settings are performed under this operating condition.

[0050] Optionally, in step S4, setting the flow parameter of the flow channel in the reactor core in the node model to a rated value includes: calculating the rated flow at zero power of the reactor based on the node model, and taking the rated flow as the rated value of the flow parameter of the flow channel in the reactor core in the node model. Specifically, in practical applications, the resistance coefficient of the flow channel in the reactor core has a greater influence on the final calculation result of the node model. Therefore, it is necessary to adopt a method with higher accuracy to calculate the resistance coefficient. In the calculation process, it is necessary to calculate the rated flow at zero power of the reactor through the established node model, and use the rated flow as the rated value of the flow parameter of the flow channel in the reactor core in the node model.

[0051] Optionally, in step S6, the stability confirmation result of the irradiated sample tube plug is obtained according to the node pressure difference, including: obtaining the critical pressure difference of 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 when the node pressure difference is less than or equal to the critical pressure difference, determining that the irradiated sample tube plug is in a stable state, otherwise determining that the irradiated sample tube plug is in an unstable state. Specifically, based on the force analysis of the irradiated sample tube plug, the critical pressure difference ΔP of the upper and lower sections of the tube plug that is stable on the core hanging basket hole seat can be obtained. cr Among them, under the refueling cold shutdown condition, the reactor pressure vessel top cover and upper internal components are lifted off, and the sample tube plug is placed on the hole seat only by gravity. That is to say, it can be understood that the force on the irradiated sample plug under the refueling cold shutdown condition is mainly its own gravity G and the buoyancy F b The pressure caused by the different pressure difference between the upper and lower ends of the pipe plug during the coolant transmission process. If the pipe plug is to be flushed away from the hole seat on the hanging basket, the upward pressure formed by the pressure difference between the upper and lower ends of the pipe plug must overcome gravity and buoyancy. The critical pressure difference of the hole seat for the irradiated sample plug to maintain stability is:

[0052]

[0053] Where S is the end surface area of ​​the tube plug. In the process of stability analysis, if the ΔP calculated by the overall model of the water filling method is less than the critical stable pressure difference ΔPcr of the hole seat, the irradiated sample tube plug will remain stable during the water filling process; otherwise, the irradiated sample tube plug will be impulsive, and there will be stability problems in the irradiated sample tube plug.

[0054] Optionally, in step S5, the water filling working mode corresponding to the nuclear power unit includes: a water filling working mode of filling water through the high-pressure safety injection system of the nuclear power unit; or a water filling working mode of filling water through the low-pressure safety injection system of the nuclear power unit. Specifically, according to the actual working conditions of the nuclear power unit, both the high-pressure safety injection system and the low-pressure safety injection system can realize the coolant of a certain pressure and flow rate to be filled into the primary circuit system and the reactor water pool through the safety injection nozzle. Among them, the low-pressure safety injection system can include low-pressure safety injection cold section injection, low-pressure safety injection hot section injection, etc.

[0055] In practical applications, when a nuclear power unit uses a high-pressure injection pump or a low-pressure injection pump to inject into the hot and cold sections of a primary circuit, the irradiated sample tube plug stability analysis method can be used to select a fast water filling method while ensuring the stability of reactor components, thereby shortening the critical path of overhaul and improving the economy of the unit.

[0056] In addition, an electronic device of the present invention may also 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 implement the above method. Specifically, according to an embodiment of the present invention, the process described with reference to the flowchart above can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed by an electronic device and when executed, it performs the above functions defined in the method of the embodiment of the present invention. The electronic device in the present invention can be a terminal such as a notebook, a desktop, a tablet computer, a smart phone, or a server.

[0057] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A method for confirming the stability of an irradiated sample tube plug, characterized in that: Applied to the process of stopping the reactor for refueling and water filling in a nuclear power unit, the method comprises the following steps: S1. Based on a preset estimation model, a node model of a primary circuit and a reactor pool in a nuclear power unit is generated, 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 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 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 a water filling working mode corresponding to the nuclear power unit according to the node model, and setting the injection flow parameter in the node model to gradually increase to a target setting value within a preset time; S6. Obtaining a node pressure difference obtained by subtracting the first preset node from the second preset node according to the node model, so as to obtain a stability confirmation result of the irradiated sample tube plug according to the node pressure difference.

2. The method for confirming the stability of an irradiated sample tube plug according to claim 1, characterized in that: In step S1, generating a node model of a primary circuit and a reactor pool in a nuclear power unit based on a preset estimation model includes: Based on the light water reactor optimal estimate model RELAP, the primary loop system and the 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 S2, When the node of the node model corresponds to a flow component, the node parameter includes 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.

4. The method for confirming the stability of an irradiated sample tube plug 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 nuclear power unit operating in a single-loop open condition with a single RRA pump.

5. The method for confirming the stability of irradiated sample tube plugs according to claim 1, characterized in that: In the step S4, setting the flow parameter of the flow channel in the reactor core in the node model to a rated value 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.

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

7. The method for confirming the stability of irradiated sample tube plugs according to claim 6, characterized in that: The preset time is 5s.

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

9. The method for confirming the stability of an irradiated sample tube plug according to claim 1, characterized in that: 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.

10. 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 9.

Images