Evaluation method and device for the causes and impacts of hollowing of the steel lining of nuclear power plant containment

Abstract

The present application provides a method and device for evaluating the causes and effects of hollowing of the steel lining of a nuclear power plant containment vessel, including: obtaining the mechanical boundary conditions of the local structural mechanical analysis model of the steel lining through finite element calculation using the overall mechanical model of the containment vessel structure; obtaining the stress condition of the bonding interface between the steel lining and the shell wall concrete through finite element calculation using the local structural mechanical analysis model of the steel lining in combination with the mechanical boundary conditions; judging whether hollowing occurs locally in the steel lining based on the stress condition of the bonding interface; if hollowing occurs, analyzing the causes of the hollowing and evaluating whether the hollowing will affect the sealing function of the steel lining; if the stress of the steel lining after hollowing does not exceed the allowable stress value of the steel material, determining that the sealing function of the steel lining is not affected. The present application solves the problem that the existing method for evaluating hollowing of the steel lining relies too much on personal experience and is difficult to evaluate the impact of hollowing on the overall sealing performance of the containment vessel by using the calculation results of the two models.

Description

Technical Field

[0001] The present application belongs to the technical field of in-service performance evaluation of nuclear power plant containment, and specifically relates to a method and device for evaluating the causes and effects of hollowing of the steel lining of a nuclear power plant containment. Background Art

[0002] The containment integral pressure test is one of the key nuclear safety-related tests performed during the commissioning and operation of various nuclear power plant types, including pressurized water reactors, heavy water reactors, and fast reactors. After the unit enters service, the test must be conducted according to a prescribed test cycle. This test is characterized by high risk, complex organization, and a long time spent on the critical path of the overhaul. This test uses dry air to pressurize the containment to the design pressure at a specific rate to simulate the conditions within the containment under design basis accident conditions. This verifies that the sealing performance and structural strength of the containment and its associated components, which serve as the nuclear safety barrier, meet the design functional requirements.

[0003] The steel lining is a key component in ensuring the containment structure's sealing performance. For example, the steel lining system used in one unit consists of thin steel plates, studs, and angle steel. The studs and angle steel are welded to the thin steel plates. The thin steel plates are 6mm thick, and the studs are φ16 bolts with an 80mm length, an 8mm thread diameter, and a 16mm nut diameter. The angle steels are primarily L125×80×10 and L75×50×8. The steel lining system serves as the formwork for the containment concrete pouring and is anchored to the concrete structure via studs and angle steel. The studs are anchored separately, while the angle steels are anchored continuously.

[0004] In theory, the steel liner, as part of the containment structure, should be fully integrated with it. However, during the containment pressure test, hollowing is often discovered through listening inspections. This phenomenon occurs when the steel liner separates from the containment concrete structure. This hollowing phenomenon easily raises concerns about the overall sealing performance of the containment. Summary of the Invention

[0005] In view of this, the present application provides a method and device for evaluating the causes and impacts of hollowing in the steel lining of a nuclear power plant containment vessel. By calculating the results based on the overall mechanical model of the containment vessel structure and the mechanical analysis model of the local structure of the steel lining with interface force units, the present application aims to solve the problem that the existing method for evaluating hollowing in the steel lining relies too much on personal experience and is difficult to evaluate the impact of hollowing on the overall sealing performance of the containment vessel.

[0006] In a first aspect, the present application provides a method for evaluating the causes and impacts of hollowing of a nuclear power plant containment steel lining. The method comprises:

[0007] Step 1: Based on the containment design drawings, the finite element method was used to establish a global mechanical model of the containment structure and a local structural mechanical analysis model of the steel liner with cohesion elements. The cohesion elements were used to simulate the interaction between the steel liner structure and the containment concrete structure.

[0008] Step 2: Perform finite element calculations on the overall mechanical model of the containment structure to obtain the mechanical boundary conditions of the local structural mechanical analysis model of the steel lining.

[0009] Step 3: Combined with the mechanical boundary conditions of the local structural mechanical analysis model of the steel lining, the finite element calculation is performed through the local structural mechanical analysis model of the steel lining to obtain the stress condition of the bonding interface between the steel lining and the shell wall concrete.

[0010] Step 4: Determine whether hollowing occurs locally in the steel lining based on the stress condition of the bonding interface between the steel lining and the shell concrete.

[0011] Step 5: If hollowing occurs locally in the steel lining, analyze the cause of the hollowing and assess whether the hollowing will affect the sealing function of the steel lining.

[0012] Step 6: If the stress of the steel lining after hollowing does not exceed the allowable stress value of the steel material, it is determined that the sealing function of the steel lining is not affected.

[0013] In a specific embodiment of the present application, the above step 1 includes:

[0014] Step 1.1: Based on the design drawings of the containment structure, use the structural analysis software platform to establish the overall mechanical model of the containment structure. When performing finite element calculation mesh division on the overall mechanical model of the containment structure, the number of units divided along the thickness of the containment structure wall shall be no less than 3.

[0015] Step 1.2: Based on the containment structure design drawings, a structural analysis software platform is used to establish a local structural mechanics analysis model of the steel liner with interface force units.

[0016] In a specific embodiment of the present application, the structural analysis software platform is ABAQUS software.

[0017] In a specific embodiment of the present application, the computer used to establish the overall mechanical model of the containment structure and the local structural mechanical analysis model of the steel lining with interface force units in step 1 has a CPU core number of no less than 8 cores, a memory size of no less than 16G, and a hard disk capacity of no less than 512G.

[0018] In a specific embodiment of the present application, the above step 2 includes:

[0019] Step 2.1, assign calculation parameters to the overall mechanical model of the containment structure. The calculation parameters of the overall mechanical model of the containment structure include material parameters, boundary conditions and load effects.

[0020] Step 2.2: Perform calculation and analysis on the overall mechanical model of the containment structure based on the calculation parameters to obtain the mechanical boundary conditions of the local structural mechanical analysis model of the steel lining.

[0021] In a specific embodiment of the present application, the above step 3 includes:

[0022] Step 3.1, assign calculation parameters to the local structural mechanics analysis model of the steel lining. The calculation parameters of the local structural mechanics analysis model of the steel lining include mechanical boundary conditions, material parameters and load effects.

[0023] Step 3.2: Obtain the damage parameters of the interface load-bearing elements by performing computational analysis on the local structural mechanics analysis model of the steel lining. The damage parameters of the interface load-bearing elements are used to characterize the stress conditions at the bonding interface between the steel lining and the shell concrete.

[0024] In a specific embodiment of the present application, the interface force unit is a cohesion unit.

[0025] The constitutive relation of the cohesion unit is expressed as follows:

[0026] Formula 1.

[0027] In formula 1, and is the interfacial bonding stress and slip value;

[0028] and is the stiffness of the ascending and descending sections in the constitutive relationship;

[0029] is the slip value corresponding to the maximum bonding stress;

[0030] is the maximum slip value.

[0031] The second aspect of the present application provides a computer device, the computer device comprising a processor and a memory. The processor is used to execute a method for evaluating the causes and effects of hollowing of a nuclear power plant containment steel lining according to the first aspect of the present application. The memory is used to store executable instructions of the processor.

[0032] A third aspect of the present application provides a computer-readable storage medium storing computer executable instructions, which, when executed by a processor, implements a method for evaluating the causes and effects of hollowing of a nuclear power plant containment steel lining according to the first aspect of the present application.

[0033] The fourth aspect of the present application provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements a method for evaluating the causes and effects of hollowing of the steel lining of a nuclear power plant containment vessel according to the first aspect of the present application.

[0034] The beneficial effects of the technical solution of this application are as follows: through the overall mechanical model of the containment structure, the mechanical boundary conditions of the local steel lining are obtained; the interface force unit is introduced into the mechanical analysis model of the local structure of the steel lining to simulate the interaction between the steel lining structure and the concrete structure of the containment; the calculation results of the overall mechanical model of the containment structure and the mechanical analysis model of the local structure of the steel lining are combined to analyze the force analysis of the steel lining structure and the force condition of the bonding interface between the steel lining and the shell concrete, and finally the force analysis of the steel lining structure and the force condition evaluation of the bonding interface between the steel lining and the shell concrete can be realized, and the cause analysis and impact evaluation of hollowing of the containment steel lining are realized. This application demonstrates the impact of hollowing on the overall sealing performance of the containment and provides a theoretical basis for the aging management of the containment of nuclear power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The figure shows a flow chart of a method for evaluating the causes and impacts of hollowing of a nuclear power plant containment steel lining, provided by one embodiment of the present application.

[0036] Figure 2a The figure shows a schematic diagram of the vertical stress of the cylinder wall at the vertical stress boundary of the area where the local structural mechanical analysis model of the steel lining is located, which is extracted from the calculation results of the overall mechanical model of the containment structure provided by one embodiment of the present application.

[0037] Figure 2b The figure shows a schematic diagram of the transverse stress of the cylinder wall at the transverse force boundary of the area where the local structural mechanical analysis model of the steel lining is located, which is extracted from the calculation results of the overall mechanical model of the containment structure provided by one embodiment of the present application.

[0038] Figure 3 The figure shows a stress diagram of the steel lining after considering the damage of the bonding interface between the steel lining and the concrete, provided by an embodiment of the present application.

[0039] Figure 4 Shown is a unit division diagram of the wall thickness direction of a containment structure provided by an embodiment of the present application.

[0040] Figure 5 Shown is a schematic diagram of an overall mechanical model of a containment structure provided in one embodiment of the present application.

[0041] Figure 6 Shown is a diagram showing the degree of damage to the bonding interface between a steel lining and concrete provided in one embodiment of the present application.

[0042] Figure 7 Shown is a schematic diagram of a local structural mechanics analysis model of a steel lining provided in one embodiment of the present application.

[0043] Figure 8 Shown is a constitutive relationship diagram of the cohesion unit between a steel lining and shell wall concrete provided in one embodiment of the present application. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0045] At least one embodiment of the present application provides a method for evaluating the causes and effects of hollowing of the containment steel lining of a nuclear power plant. The method for evaluating the causes and effects of hollowing of the containment steel lining of a nuclear power plant is applicable to the aging management of the containment during the service life of the nuclear power plant. Figure 1 The method for evaluating the causes and impacts of hollowing of the containment steel lining of a nuclear power plant includes the following steps 1 to 6.

[0046] Step 1: Based on the containment design drawings, the finite element method was used to establish a global mechanical model of the containment structure and a local structural mechanical analysis model of the steel liner with cohesion elements. The cohesion elements were used to simulate the interaction between the steel liner structure and the containment concrete structure.

[0047] It should be noted that the overall mechanical model of the containment structure (or the overall containment model) is a finite element model for the mechanical analysis of the overall containment structure. The local mechanical analysis model of the steel liner (or the local steel liner model) is a finite element model for the mechanical analysis of the local steel liner structure.

[0048] The structural geometry of the overall mechanical model of the containment structure should be consistent with the design drawings. The model range of the local structural mechanical analysis model for the steel liner can be selected as the area enclosed by angle steel. The overall mechanical model of the containment structure includes the containment cylinder, dome, floor, prestressed steel strands within the shell, and local areas such as the gate. The overall mechanical model of the containment structure is meshed using solid elements, and the boundary conditions of the overall mechanical model of the containment structure are set to constrain the displacement of the floor. The prestressed load in the overall mechanical model of the containment structure can be applied through an equivalent cooling method.

[0049] Step 2: Perform finite element calculations on the overall mechanical model of the containment structure to obtain the mechanical boundary conditions of the local structural mechanical analysis model of the steel lining.

[0050] Specifically, the mechanical boundary conditions of the local structural mechanical analysis model of the steel lining can be obtained by calculating and analyzing the overall structure of the containment in the overall mechanical model of the containment structure. Here, the vertical and horizontal force boundaries of the area where the local structural mechanical analysis model of the steel lining is located are extracted, such as Figure 2a and Figure 2b shown. Figure 2a "S, S33" represents the normal stress along the vertical direction of the containment. Figure 2b “S, S22” represents the normal stress along the annular direction of the containment.

[0051] Step 3: Combined with the mechanical boundary conditions of the local structural mechanical analysis model of the steel lining, the finite element calculation is performed through the local structural mechanical analysis model of the steel lining to obtain the stress condition of the bonding interface between the steel lining and the shell wall concrete.

[0052] Step 4: Determine whether hollowing occurs locally in the steel lining based on the stress condition of the bonding interface between the steel lining and the shell concrete.

[0053] Step 5: If hollowing occurs locally in the steel lining, analyze the cause of the hollowing and assess whether the hollowing will affect the sealing function of the steel lining.

[0054] Step 6: If the stress of the steel lining after hollowing does not exceed the allowable stress value of the steel material, it is determined that the sealing function of the steel lining is not affected.

[0055] Specifically, if hollowing occurs locally in the steel lining, the bonding interface between the steel lining and the shell concrete has completely failed. In this case, the stress of the steel lining after hollowing can be judged based on the stress on weak parts such as the steel lining steel plate, studs, and the welding position between the studs and the steel plate: if it does not exceed the allowable stress value of the steel material, the sealing function of the steel lining will not be affected. Figure 3 shown. Figure 3 “S, Mises” refers to the equivalent stress of the steel lining.

[0056] According to the technical solution provided in the embodiment of the present application, the mechanical boundary conditions of the local steel lining are obtained through the overall mechanical model of the containment structure; an interface force unit is introduced into the mechanical analysis model of the local structure of the steel lining to simulate the interaction between the steel lining structure and the concrete structure of the containment; the calculation results of the overall mechanical model of the containment structure and the mechanical analysis model of the local structure of the steel lining are combined to analyze the force analysis of the steel lining structure and the force condition of the bonding interface between the steel lining and the shell concrete, and finally the force analysis of the steel lining structure and the force condition evaluation of the bonding interface between the steel lining and the shell concrete can be realized, and the cause analysis and impact evaluation of hollowing of the containment steel lining are realized. The embodiment of the present application demonstrates the influence of hollowing on the overall sealing performance of the containment, and provides a theoretical basis for the aging management of the containment of nuclear power plants.

[0057] In at least one embodiment of the present application, the above step 1 includes:

[0058] Step 1.1: Based on the design drawings of the containment structure, the overall mechanical model of the containment structure is established using the structural analysis software platform. When the finite element calculation mesh is divided for the overall mechanical model of the containment structure, the number of units divided along the thickness of the containment structure wall is not less than 3, such as Figure 4 shown.

[0059] Step 1.2: Based on the containment structure design drawings, a structural analysis software platform is used to establish a local structural mechanics analysis model of the steel liner with interface force units.

[0060] In at least one embodiment of the present application, the structural analysis software platform is ABAQUS software.

[0061] When establishing the overall mechanical model of the containment structure and the mechanical analysis model of the local structure of the steel liner with interface force units in step 1, the computer hardware configuration to be used can be selected according to actual needs.

[0062] For example, in at least one embodiment of the present application, the computer used to establish the overall mechanical model of the containment structure and the local structural mechanical analysis model of the steel lining with interface force units in step 1 has a CPU core number of no less than 8 cores, a memory size of no less than 16G, and a hard disk capacity of no less than 512G.

[0063] In at least one embodiment of the present application, the above step 2 includes:

[0064] Step 2.1, assign calculation parameters to the overall mechanical model of the containment structure. The calculation parameters of the overall mechanical model of the containment structure include material parameters, boundary conditions and load effects.

[0065] Step 2.2: Perform calculation and analysis on the overall mechanical model of the containment structure based on the calculation parameters to obtain the mechanical boundary conditions of the local structural mechanical analysis model of the steel lining.

[0066] In some embodiments, the material parameters and load effects of the overall mechanical model of the containment structure are determined according to the design drawings, and the boundary conditions are in the form of constrained raft foundations, such as Figure 5 shown.

[0067] In at least one embodiment of the present application, the above step 3 includes:

[0068] Step 3.1, assign calculation parameters to the local structural mechanics analysis model of the steel lining. The calculation parameters of the local structural mechanics analysis model of the steel lining include mechanical boundary conditions, material parameters and load effects.

[0069] In some embodiments, the mechanical boundary conditions of the local structural mechanics analysis model for the steel liner are assigned based on the calculation results of the overall mechanical model of the containment structure, including vertical and lateral forces. The material parameters of the local structural mechanics analysis model for the steel liner can be derived from test data or reference values provided by an association. The load action of the local structural mechanics analysis model for the steel liner can be determined based on the internal pressure and temperature values under a loss of coolant accident (LOCA) as provided in the design drawings.

[0070] Step 3.2: Obtain the damage parameters of the interface load-bearing elements by performing computational analysis on the local structural mechanics analysis model of the steel lining. The damage parameters of the interface load-bearing elements are used to characterize the stress conditions at the bonding interface between the steel lining and the shell concrete.

[0071] It should be noted that the stress condition of the bonding interface between the steel lining and the shell wall concrete is quantified by the damage parameter (SDEG) of the interface stress unit. SDEG represents the degree of damage to the interface structure. The larger the value, the more severe the damage. When SDEG is 0, it means that the material has not been damaged. When SDEG is 1, it means that the bonding interface between the steel lining and the shell wall concrete has been completely destroyed. At this time, a gap may appear between the steel lining and the concrete, and a hollow sound can be found by knocking, such as Figure 6 shown.

[0072] As long as the interface force unit can be used to simulate the interaction between the steel lining structure and the containment concrete structure, the embodiment of the present application does not make any specific limitations on the interface force unit.

[0073] For example, in at least one embodiment of the present application, the interface force unit is a cohesion unit.

[0074] The constitutive relation of the cohesion unit is expressed as follows:

[0075] Formula 1.

[0076] In formula 1, and is the interfacial bonding stress and slip value;

[0077] and is the stiffness of the ascending and descending sections in the constitutive relationship;

[0078] The maximum bonding stress The corresponding slip value;

[0079] is the maximum slip value.

[0080] It should be noted that the constitutive parameters of the cohesion unit between the steel lining and the shell concrete (i.e. the parameter values in Formula 1) can use experimental data. If there are no experimental data, the bonding parameter values of the plain round steel bars and concrete provided by the International Prestressed Concrete Association FIP (2010) can be referred to. The International Prestressed Concrete Association FIP (2010) refers to the "Fib Model Code for Concrete Structures 2010". The local structural mechanics analysis model of the steel lining also considers the temperature effect on the steel lining caused by the temperature change in the shell during the overall pressure test of the containment. The local structural mechanics analysis model of the steel lining is as follows: Figure 7 As shown in the figure, the constitutive relation of the cohesion unit is as follows: Figure 8 shown. Figure 7 In the figure, 10 represents the containment concrete structure, 20 represents the steel lining, 30 represents the cohesion unit, and 40 represents the anchor.

[0081] At least one embodiment of the present application further provides a computer device comprising a processor and a memory. The processor is configured to execute a method for evaluating the causes and effects of hollowing of the steel lining of a nuclear power plant containment vessel, as provided in any of the above embodiments of the present application. The memory is configured to store executable instructions for the processor, such as an application program. The number of processors may be one or more. The application program stored in the memory may include one or more modules, each corresponding to a set of instructions. Furthermore, the processor is configured to execute instructions to execute the above-described method for evaluating the causes and effects of hollowing of the steel lining of a nuclear power plant containment vessel.

[0082] The computer device may also include a power supply component configured to manage power of the computer device, a wired or wireless network interface configured to connect the computer device to a network, and an input / output (I / O) interface. The computer device may operate based on an operating system stored in the memory, such as Windows Server 2003. TM , Mac OSX TM , Unix TM , Linux TM , FreeBSD TM or similar.

[0083] At least one embodiment of the present application further provides a computer-readable storage medium having computer-executable instructions stored thereon. When executed by a processor, the executable instructions implement a method for evaluating the causes and effects of hollowing of a nuclear power plant containment steel lining, as provided in any of the above embodiments of the present application.

[0084] A non-transitory computer-readable storage medium, when executed by a processor of a computer device, enables the computer device to execute the method for assessing the causes and impacts of hollowing in the steel lining of a nuclear power plant containment vessel. The method for assessing the causes and impacts of hollowing in the steel lining of a nuclear power plant containment vessel is executed by an agent program.

[0085] Those skilled in the art will appreciate that the algorithmic steps of each example described in conjunction with the embodiments disclosed in this application can be implemented using electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0086] At least one embodiment of the present application further provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements a method for evaluating the causes and effects of hollowing of the steel lining of a nuclear power plant containment vessel provided in any of the above embodiments of the present application.

[0087] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a computer program product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method for evaluating the causes and effects of hollowing of the steel lining of the nuclear power plant containment vessel in each embodiment of the present application. The aforementioned storage medium includes various media that can store program check codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0088] It should be noted that the combination of the various technical features in the embodiments of the present application is not limited to the combination described in the embodiments of the present application or the combination described in the specific embodiments. All technical features described in the present application can be freely combined or combined in any way unless there is a contradiction between them.

[0089] As used in this application and the claims, unless the context clearly indicates otherwise, the words "a," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the term "comprising" only indicates the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0090] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for evaluating the causes and impacts of hollowing of the containment steel lining of a nuclear power plant, characterized in that: include: Step 1: Based on the design drawings of the containment structure, the finite element method is used to establish the overall mechanical model of the containment structure and the local structural mechanical analysis model of the steel liner with cohesion units. The cohesion units are used to simulate the interaction between the steel liner structure and the containment concrete structure. Step 2: Perform finite element calculation on the overall mechanical model of the containment structure to obtain the mechanical boundary conditions of the local structural mechanical analysis model of the steel lining; Step 3: Combined with the mechanical boundary conditions of the local structural mechanical analysis model of the steel lining, a finite element calculation is performed through the local structural mechanical analysis model of the steel lining to obtain the stress condition of the bonding interface between the steel lining and the shell wall concrete; Step 4: Determine whether hollowing occurs locally in the steel lining based on the stress condition of the bonding interface between the steel lining and the shell concrete; Step 5: If hollowing occurs locally in the steel lining, analyze the cause of the hollowing and assess whether the hollowing will affect the sealing function of the steel lining. Step 6: If the stress of the steel lining after hollowing does not exceed the allowable stress value of the steel material, it is determined that the sealing function of the steel lining is not affected.

2. The method for evaluating the causes and effects of hollowing of the containment steel lining of a nuclear power plant according to claim 1, characterized in that: Step 1 includes: Step 1.1: Based on the design drawings of the containment structure, use the structural analysis software platform to establish the overall mechanical model of the containment structure. When performing finite element calculation meshing on the overall mechanical model of the containment structure, the number of cells divided along the thickness of the containment structure wall should be no less than 3; Step 1.2: Based on the containment structure design drawings, a structural analysis software platform is used to establish a local structural mechanics analysis model of the steel liner with interface force units.

3. The method for evaluating the causes and effects of hollowing of the containment steel lining of a nuclear power plant according to claim 2, characterized in that: The structural analysis software platform is ABAQUS software.

4. The method for evaluating the causes and effects of hollowing of the containment steel lining of a nuclear power plant according to claim 1, characterized in that: Step 2 includes: Step 2.1, assign calculation parameters to the overall mechanical model of the containment structure. The calculation parameters of the overall mechanical model of the containment structure include material parameters, boundary conditions, and load effects; Step 2.2: Perform calculation and analysis on the overall mechanical model of the containment structure based on the calculation parameters to obtain the mechanical boundary conditions of the local structural mechanical analysis model of the steel lining.

5. The method for evaluating the causes and effects of hollowing of the containment steel lining of a nuclear power plant according to claim 1, characterized in that: Step 3 includes: Step 3.1, assign calculation parameters to the local structural mechanics analysis model of the steel lining, where the calculation parameters of the local structural mechanics analysis model of the steel lining include mechanical boundary conditions, material parameters, and load effects; Step 3.2: By performing calculation and analysis on the local structural mechanics analysis model of the steel lining, the damage parameters of the interface force unit are obtained. The damage parameters of the interface force unit are used to characterize the stress condition of the bonding interface between the steel lining and the shell wall concrete.

6. The method for evaluating the causes and effects of hollowing of the containment steel lining of a nuclear power plant according to claim 1, characterized in that: The interface force unit is the cohesion unit. The constitutive relation of the cohesion unit is expressed as follows: Formula 1, In formula 1, and is the interfacial bonding stress and slip value; and is the stiffness of the ascending and descending sections in the constitutive relationship; The maximum bonding stress The corresponding slip value; is the maximum slip value.

7. A computer device, characterized in that: include: A processor, configured to execute a method for evaluating the causes and effects of hollowing of a steel lining of a nuclear power plant containment vessel according to any one of claims 1 to 6; and a memory for storing executable instructions for the processor.

8. A computer-readable storage medium having computer-executable instructions stored thereon, characterized in that: When the executable instructions are executed by the processor, a method for evaluating the causes and effects of hollowing of the steel lining of a nuclear power plant containment vessel according to any one of claims 1 to 6 is implemented.

9. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, a method for evaluating the causes and effects of hollowing of a nuclear power plant containment vessel steel lining according to any one of claims 1 to 6 is implemented.

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