Xun Zhang, Jianfei Hou, Heino Zimmermann, Zhaohui Xiang
The performance degradation and latent fault of equipment may cause unplanned outage or power reduction in nuclear power plant, as a result, the operation and maintenance costs increase. By developing a nuclear power plant digital twin, some potential abnormalities can be detected and predictive maintenance can be performed to avoid equipment failure. So, a digital twin for main thermodynamic systems in an operating nuclear power plant is built by using EPOS code to monitor its thermal performance. Firstly, a thermodynamic system simulation model containing primary loop, secondary loop and cooling system is developed according to design documents, and the design parameters under full load are used to calculate all the equipment’s nominal values. Then the thermal performance of specific equipment is identified under partial loads. Some fitting process are needed to find the correlations between different variables and the fitting curves will be embedded into the equipment model if necessary. Moreover, a data reconciliation technique is used to assimilate the system model depending on measurements of operating nuclear power plant and the digital twin is gained at last. The result shows that the digital twin can represent the thermal performance of real plant very well although a few of measure inconsistencies are detected during the data reconciliation process.
{"title":"Preliminary Research on Digital Twin of Main Thermodynamic Systems in Nuclear Power Plant for Thermal Performance Monitoring","authors":"Xun Zhang, Jianfei Hou, Heino Zimmermann, Zhaohui Xiang","doi":"10.1115/icone29-91244","DOIUrl":"https://doi.org/10.1115/icone29-91244","url":null,"abstract":"\u0000 The performance degradation and latent fault of equipment may cause unplanned outage or power reduction in nuclear power plant, as a result, the operation and maintenance costs increase. By developing a nuclear power plant digital twin, some potential abnormalities can be detected and predictive maintenance can be performed to avoid equipment failure. So, a digital twin for main thermodynamic systems in an operating nuclear power plant is built by using EPOS code to monitor its thermal performance. Firstly, a thermodynamic system simulation model containing primary loop, secondary loop and cooling system is developed according to design documents, and the design parameters under full load are used to calculate all the equipment’s nominal values. Then the thermal performance of specific equipment is identified under partial loads. Some fitting process are needed to find the correlations between different variables and the fitting curves will be embedded into the equipment model if necessary. Moreover, a data reconciliation technique is used to assimilate the system model depending on measurements of operating nuclear power plant and the digital twin is gained at last. The result shows that the digital twin can represent the thermal performance of real plant very well although a few of measure inconsistencies are detected during the data reconciliation process.","PeriodicalId":422334,"journal":{"name":"Volume 12: Innovative and Smart Nuclear Power Plant Design","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127111402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A nuclear power plant adopts electrolyzing saline to prepare sodium hypochlorite solution with the effective chlorine concentration no less than 8000 mg/L, which is provided to the circulating water system, essential service water system, industrial water system, potable water system, and demineralized water production system as biocide. The system name of sodium hypochlorite solution production by electrolyzing saline is the circulating water treatment system, which includes salt storage, dilute saline preparation, sodium hypochlorite solution production, sodium hypochlorite solution storage and dosing, etc. In system process design, the system automatic operation is realized by optimizing the system design and operation control scheme, and setting online monitoring instruments, automatic valves and control system to reduce the intervention of operators. In addition, the hydrogen exhaust fans are set next to the outdoor sodium hypochlorite storage tanks for mechanical hydrogen exhaust, so that the hydrogen can be quickly diluted and discharged to the atmosphere to ensure the safety of system operation. Combined with the engineering practice, this paper expounds the design overview of circulating water treatment system from the aspects of user requirements, optimization design of each process link and process equipment configuration, which can provide reference for the process design of circulating water treatment system in subsequent nuclear power plants.
{"title":"Design Overview for Process System of Chlorine Production by Electrolyzing Saline in the Nuclear Power Plant","authors":"Rui Wang, Kehao Zeng, Kechen Xu, Hongmei Yan, Wei Bai, Jing Li","doi":"10.1115/icone29-90923","DOIUrl":"https://doi.org/10.1115/icone29-90923","url":null,"abstract":"\u0000 A nuclear power plant adopts electrolyzing saline to prepare sodium hypochlorite solution with the effective chlorine concentration no less than 8000 mg/L, which is provided to the circulating water system, essential service water system, industrial water system, potable water system, and demineralized water production system as biocide. The system name of sodium hypochlorite solution production by electrolyzing saline is the circulating water treatment system, which includes salt storage, dilute saline preparation, sodium hypochlorite solution production, sodium hypochlorite solution storage and dosing, etc. In system process design, the system automatic operation is realized by optimizing the system design and operation control scheme, and setting online monitoring instruments, automatic valves and control system to reduce the intervention of operators. In addition, the hydrogen exhaust fans are set next to the outdoor sodium hypochlorite storage tanks for mechanical hydrogen exhaust, so that the hydrogen can be quickly diluted and discharged to the atmosphere to ensure the safety of system operation. Combined with the engineering practice, this paper expounds the design overview of circulating water treatment system from the aspects of user requirements, optimization design of each process link and process equipment configuration, which can provide reference for the process design of circulating water treatment system in subsequent nuclear power plants.","PeriodicalId":422334,"journal":{"name":"Volume 12: Innovative and Smart Nuclear Power Plant Design","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129799248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Haiyan Chen, Licheng Tian, Zhigang Zhou, Jiaojiao Yang
The intelligent process system flow chart of the nuclear power is based on the symbol library. Each component and its attributes on the system flow chart are stored in a digital form for reference to subsequent projects. The content of this paper is the automatic generation of Definitive Data Assembly and the automatic association of the drawing interface of the intelligent process system flow chart by using Diagrams. It is an optimization of the intelligent process system flow chart for the application of Diagrams by using information technology and computer language. The Definitive Data Assembly automatic generation function realizes generating Definitive Data Assembly statistical table at a fixed position of the drawing surface, and improves the neat specification of the drawing information; The single drawing Definitive Data Assembly statistical table is automatically generated, and the batch drawing Definitive Data Assembly statistical table can be automatically generated, one-click operation, which greatly improves the work efficiency; at the same time, solves the problem of disordered management of Definitive Data Assembly. Optimized the application of Diagrams to draw the interface merging function of the intelligent process system flow chart, which greatly reduced the number of files in the project file XXXMAC->Schematic path, reduced the selection obstacles and improved the correct rate; Developed interface-connected menus, one-click operation, saving time for drafters, automatically deleting MAC files, reducing the workload of project administrators, and releasing project storage space, improving work efficiency. The research results of this paper are applied to draw the process system flow chart of many specialities such as nuclear island system, radioactive waste management, hydraulic technology, HVAC, chemical water, conventional island machinery, etc.
{"title":"Research and Application on Drawing Method of Optimizing for the Intelligent Process System Flow Chart of the Nuclear Power","authors":"Haiyan Chen, Licheng Tian, Zhigang Zhou, Jiaojiao Yang","doi":"10.1115/icone29-92101","DOIUrl":"https://doi.org/10.1115/icone29-92101","url":null,"abstract":"\u0000 The intelligent process system flow chart of the nuclear power is based on the symbol library. Each component and its attributes on the system flow chart are stored in a digital form for reference to subsequent projects. The content of this paper is the automatic generation of Definitive Data Assembly and the automatic association of the drawing interface of the intelligent process system flow chart by using Diagrams. It is an optimization of the intelligent process system flow chart for the application of Diagrams by using information technology and computer language. The Definitive Data Assembly automatic generation function realizes generating Definitive Data Assembly statistical table at a fixed position of the drawing surface, and improves the neat specification of the drawing information; The single drawing Definitive Data Assembly statistical table is automatically generated, and the batch drawing Definitive Data Assembly statistical table can be automatically generated, one-click operation, which greatly improves the work efficiency; at the same time, solves the problem of disordered management of Definitive Data Assembly. Optimized the application of Diagrams to draw the interface merging function of the intelligent process system flow chart, which greatly reduced the number of files in the project file XXXMAC->Schematic path, reduced the selection obstacles and improved the correct rate; Developed interface-connected menus, one-click operation, saving time for drafters, automatically deleting MAC files, reducing the workload of project administrators, and releasing project storage space, improving work efficiency. The research results of this paper are applied to draw the process system flow chart of many specialities such as nuclear island system, radioactive waste management, hydraulic technology, HVAC, chemical water, conventional island machinery, etc.","PeriodicalId":422334,"journal":{"name":"Volume 12: Innovative and Smart Nuclear Power Plant Design","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121690064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The typical third generation pressurized water reactor nuclear power plants trigger safety injection signal to actuate the emergency core cooling system based on the saturation margin of coolant in hot legs of primary circuit, i.e. ΔPsat in hot legs, which represents the difference between saturation pressure and actual pressure in hot legs. In order to identify the risk of spurious safety injection during falling the reactor back to safety shutdown state after steam generator isolation following an accident on secondary side for which safety injection is unnecessary, this paper analyzes thermo hydraulic phenomenon in the hot legs where the steam generators are isolated. By selecting reasonable monitoring parameters, the risk monitoring curve of spurious safety injection, which clearly marks off the risk zone of spurious safety injection, is plotted based on the actuation logic of safety injection. The curve has been integrated into the post-accident operating state monitoring and tracing system for primary circuit, and has been verified and validated thanks to the full scope simulator. It is concluded that the risk of spurious safety injection can be dynamically and effectively monitored following the accidents on secondary side, so that operators can timely take appropriate measures to avoiding spurious safety injection and fall the reactor back to safety shutdown state smoothly.
{"title":"Risk Monitoring of Spurious Safety Injection in Pressurized Water Reactor Nuclear Power Plants","authors":"Yu Huang, Zhenying Jiao, Zhen-Ying Wang, Taike Wang, Kaihe Kong, Min Li, Jian-wen Zhang","doi":"10.1115/icone29-92126","DOIUrl":"https://doi.org/10.1115/icone29-92126","url":null,"abstract":"\u0000 The typical third generation pressurized water reactor nuclear power plants trigger safety injection signal to actuate the emergency core cooling system based on the saturation margin of coolant in hot legs of primary circuit, i.e. ΔPsat in hot legs, which represents the difference between saturation pressure and actual pressure in hot legs. In order to identify the risk of spurious safety injection during falling the reactor back to safety shutdown state after steam generator isolation following an accident on secondary side for which safety injection is unnecessary, this paper analyzes thermo hydraulic phenomenon in the hot legs where the steam generators are isolated. By selecting reasonable monitoring parameters, the risk monitoring curve of spurious safety injection, which clearly marks off the risk zone of spurious safety injection, is plotted based on the actuation logic of safety injection. The curve has been integrated into the post-accident operating state monitoring and tracing system for primary circuit, and has been verified and validated thanks to the full scope simulator. It is concluded that the risk of spurious safety injection can be dynamically and effectively monitored following the accidents on secondary side, so that operators can timely take appropriate measures to avoiding spurious safety injection and fall the reactor back to safety shutdown state smoothly.","PeriodicalId":422334,"journal":{"name":"Volume 12: Innovative and Smart Nuclear Power Plant Design","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130480082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to solve the digital transformation problems faced by Jiangsu Nuclear Power Station (TNPS) under the complex situation, and to benchmark advanced enterprises to improve the current digitalization level, TNPS established a special organization to carry out the V-type system construction method which covers user needs, functional requirements, architecture design, detailed design, code implementation, unit testing, integration testing, system testing, acceptance testing, etc. TNPS is carrying out the top-level design and application implementation of intelligent station, support platform and network construction and existing information systems based on the foundation functional and digital transformation, smart application and decision-making platform construction as the main body of the smart power plant implementation plan, and combed the application scenarios from the four dimensions of “personnel, equipment, environment, and operation”, and introduced smart nuclear power using smart construction sites and smart outage as examples Implementation content and solutions for typical applications. This work has advanced design and complete system, which has certain reference significance for nuclear power enterprises to carry out digital and intelligent transformation.
{"title":"Research on Smart Nuclear Power Construction Based on Digitalization and System Engineering in TNPS","authors":"Qiang Yang","doi":"10.1115/icone29-91570","DOIUrl":"https://doi.org/10.1115/icone29-91570","url":null,"abstract":"\u0000 In order to solve the digital transformation problems faced by Jiangsu Nuclear Power Station (TNPS) under the complex situation, and to benchmark advanced enterprises to improve the current digitalization level, TNPS established a special organization to carry out the V-type system construction method which covers user needs, functional requirements, architecture design, detailed design, code implementation, unit testing, integration testing, system testing, acceptance testing, etc. TNPS is carrying out the top-level design and application implementation of intelligent station, support platform and network construction and existing information systems based on the foundation functional and digital transformation, smart application and decision-making platform construction as the main body of the smart power plant implementation plan, and combed the application scenarios from the four dimensions of “personnel, equipment, environment, and operation”, and introduced smart nuclear power using smart construction sites and smart outage as examples Implementation content and solutions for typical applications. This work has advanced design and complete system, which has certain reference significance for nuclear power enterprises to carry out digital and intelligent transformation.","PeriodicalId":422334,"journal":{"name":"Volume 12: Innovative and Smart Nuclear Power Plant Design","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117277899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Distributed Control System (DCS) is regarded as the “brain” of nuclear power plant due to its function required in guarding nuclear safety. Power supply system is vital to supply electric power for DCS to maintain normal operation. Distribution design requirements of DCS power supply system are discussed firstly on analyzing the requirements of IEEE, IEC, etc. Combining with the comparative analysis of power supply schemes of DCS system in typical nuclear power plants based on CPR1000, AP1000 and EPR, key factors restricting the reliability of DCS power supply system are analyzed based on relevant design rules and standards in this paper. The method of improving the reliability of DCS power supply system is explored by analyzing the type of power supply, system design, equipment selection and design of electrical raceway. Thus a new high reliability power supply scheme for DCS system is presented based on mature equipment manufacturing technology. The scheme enhances the reliability, stability and flexibility of the distribution system by reducing the converting process on distribution path, increasing the design of cross-tie between divisions, and making full use of the advantages of DC distribution system. Through system operation analysis, equipment analysis and fault response analysis, this paper discussed the high reliability and feasibility of the new scheme, providing a new research direction for the design of DC system in nuclear power plant.
{"title":"Study on a High Reliability Power Supply Scheme for Distributed Control System of Nuclear Power Plant","authors":"Tian Hongpeng, Zhang Lin","doi":"10.1115/icone29-91950","DOIUrl":"https://doi.org/10.1115/icone29-91950","url":null,"abstract":"\u0000 Distributed Control System (DCS) is regarded as the “brain” of nuclear power plant due to its function required in guarding nuclear safety. Power supply system is vital to supply electric power for DCS to maintain normal operation. Distribution design requirements of DCS power supply system are discussed firstly on analyzing the requirements of IEEE, IEC, etc. Combining with the comparative analysis of power supply schemes of DCS system in typical nuclear power plants based on CPR1000, AP1000 and EPR, key factors restricting the reliability of DCS power supply system are analyzed based on relevant design rules and standards in this paper. The method of improving the reliability of DCS power supply system is explored by analyzing the type of power supply, system design, equipment selection and design of electrical raceway. Thus a new high reliability power supply scheme for DCS system is presented based on mature equipment manufacturing technology. The scheme enhances the reliability, stability and flexibility of the distribution system by reducing the converting process on distribution path, increasing the design of cross-tie between divisions, and making full use of the advantages of DC distribution system. Through system operation analysis, equipment analysis and fault response analysis, this paper discussed the high reliability and feasibility of the new scheme, providing a new research direction for the design of DC system in nuclear power plant.","PeriodicalId":422334,"journal":{"name":"Volume 12: Innovative and Smart Nuclear Power Plant Design","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127903664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During the operation of a nuclear power plant, many main systems will generate variety of radioactive spent filter elements. These filter elements are main solid waste which need to be replaced regularly to keep safety of these systems. Because these filter elements have a certain level of radioactivity, the replacement operation has a higher risk. Therefore, according to the national and nuclear power plant radioactive waste regulations, it is necessary to ensure the safe and reliable operation of the radiation protection, make sure that operator and facilities are protected from radiation exposure or minimized. Based on the analysis of the filter element replacement process and equipment of domestic nuclear power units in service, combined with the requirements of newel construction of intelligent nuclear power plants, it is necessary to propose a radioactive spent filter element intelligent replacement ROBOT program. This paper discusses the design scheme of a new intelligent replacement robot for radioactive spent filter elements, and key issues involving fully automatic replacement technology for radioactive filter elements, such as filter layout and filter element replacement process optimization, robot grabbing actuator design, robot positioning mechanism design and accuracy guarantee, etc. have been systematically studied. A set of robot systems with intelligent replacement of radioactive irrationality have been developed. The test has been verified and the technical conditions for implementation in NPP have been met.
{"title":"Design and Development of Intelligent Replacement Robot for Radioactive Spent Filter Element in NPP and Its Performance Validation","authors":"Yongjun Ge, Yishan Lin, Honghu Xie, Jinchun Yang","doi":"10.1115/icone29-93482","DOIUrl":"https://doi.org/10.1115/icone29-93482","url":null,"abstract":"\u0000 During the operation of a nuclear power plant, many main systems will generate variety of radioactive spent filter elements. These filter elements are main solid waste which need to be replaced regularly to keep safety of these systems. Because these filter elements have a certain level of radioactivity, the replacement operation has a higher risk. Therefore, according to the national and nuclear power plant radioactive waste regulations, it is necessary to ensure the safe and reliable operation of the radiation protection, make sure that operator and facilities are protected from radiation exposure or minimized. Based on the analysis of the filter element replacement process and equipment of domestic nuclear power units in service, combined with the requirements of newel construction of intelligent nuclear power plants, it is necessary to propose a radioactive spent filter element intelligent replacement ROBOT program. This paper discusses the design scheme of a new intelligent replacement robot for radioactive spent filter elements, and key issues involving fully automatic replacement technology for radioactive filter elements, such as filter layout and filter element replacement process optimization, robot grabbing actuator design, robot positioning mechanism design and accuracy guarantee, etc. have been systematically studied. A set of robot systems with intelligent replacement of radioactive irrationality have been developed. The test has been verified and the technical conditions for implementation in NPP have been met.","PeriodicalId":422334,"journal":{"name":"Volume 12: Innovative and Smart Nuclear Power Plant Design","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115200661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Earthquake is always an important consideration when constructing nuclear power plants. There are many studies on how to resist or avoid earthquake damage. And recently more and more seismic isolation technology has been applied to nuclear structure in nuclear power plants using isolators mainly made of rubber which can not only bear the vertical load, but also reduce the response of seismic on the upper structure due to their low lateral stiffness so as to improve the safety of the nuclear structure in the earthquake. Compared with traditional anti-seismic technology, seismic isolation can make the design of the main structure of nuclear power plants achieve standardization unrestricted by the magnitude of design ground motion. The two main categories of seismic isolators are elastomeric bearings and spherical sliding bearings. And low damping bearings (LDR), lead rubber bearings (LR) and spherical sliding bearings (FP) are currently considered sufficiently well characterized for use in nuclear facilities. However, the rubber which is the main material of elastomeric bearings cannot withstand high temperature, so the properties of the bearings might be affected and even lost under the complex and severe environment of nuclear power plants, which could compromise the safety of nuclear reactor. In addition, both rubber bearings and spherical sliding bearings can only apply to horizontal seismic isolation. The metal springs have more stable performance than rubber under high temperature condition and also has better isolation effect. Springs are usually made of solid spring wire by metal forming. In production practice, springs are used for vertical isolation because of their low vertical stiffness, and calculations show that they also work in the lateral direction. Springs have been widely used for vibration isolation in many light load and high requirements situations like precision instruments at this stage, but need more research to be applied in nuclear structure of nuclear facilities. Compared with air spring, under the same load-bearing capacity, the stiffness of solid spring is higher, which leads to the higher natural frequency of the isolation system, so it is not suitable for the situation that requires low frequency and heavy load. This paper tries to use springs made of hollow wire to solve the problem. In this paper, some research results of hollow springs are given, including frequency and damping property when filled with damping materials. In addition, a calculation formula of hollow springs’ mechanical property, including the vertical and lateral stiffness and carrying capacity, is derived, and the finite element calculation are used to validate the formula. And the paper also gives a finite element calculation case on how the hollow spring reduce the natural frequency of an isolation system.
{"title":"Study on Application of Hollow Springs in Seismic Isolation in Nuclear Power Plants","authors":"Nannan Hou, Jianling Dong","doi":"10.1115/icone29-90341","DOIUrl":"https://doi.org/10.1115/icone29-90341","url":null,"abstract":"\u0000 Earthquake is always an important consideration when constructing nuclear power plants. There are many studies on how to resist or avoid earthquake damage. And recently more and more seismic isolation technology has been applied to nuclear structure in nuclear power plants using isolators mainly made of rubber which can not only bear the vertical load, but also reduce the response of seismic on the upper structure due to their low lateral stiffness so as to improve the safety of the nuclear structure in the earthquake. Compared with traditional anti-seismic technology, seismic isolation can make the design of the main structure of nuclear power plants achieve standardization unrestricted by the magnitude of design ground motion.\u0000 The two main categories of seismic isolators are elastomeric bearings and spherical sliding bearings. And low damping bearings (LDR), lead rubber bearings (LR) and spherical sliding bearings (FP) are currently considered sufficiently well characterized for use in nuclear facilities. However, the rubber which is the main material of elastomeric bearings cannot withstand high temperature, so the properties of the bearings might be affected and even lost under the complex and severe environment of nuclear power plants, which could compromise the safety of nuclear reactor. In addition, both rubber bearings and spherical sliding bearings can only apply to horizontal seismic isolation.\u0000 The metal springs have more stable performance than rubber under high temperature condition and also has better isolation effect. Springs are usually made of solid spring wire by metal forming. In production practice, springs are used for vertical isolation because of their low vertical stiffness, and calculations show that they also work in the lateral direction. Springs have been widely used for vibration isolation in many light load and high requirements situations like precision instruments at this stage, but need more research to be applied in nuclear structure of nuclear facilities.\u0000 Compared with air spring, under the same load-bearing capacity, the stiffness of solid spring is higher, which leads to the higher natural frequency of the isolation system, so it is not suitable for the situation that requires low frequency and heavy load. This paper tries to use springs made of hollow wire to solve the problem. In this paper, some research results of hollow springs are given, including frequency and damping property when filled with damping materials. In addition, a calculation formula of hollow springs’ mechanical property, including the vertical and lateral stiffness and carrying capacity, is derived, and the finite element calculation are used to validate the formula. And the paper also gives a finite element calculation case on how the hollow spring reduce the natural frequency of an isolation system.","PeriodicalId":422334,"journal":{"name":"Volume 12: Innovative and Smart Nuclear Power Plant Design","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122035017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The internal conditions and surface defects of key equipment in nuclear power plant (NPP) are mainly detected though non-destructive testing (NDT) technology, which is the key basis for maintenance and diagnosis of nuclear power main equipment. At present, there are many types and huge quantities of NDT data. Due to the lack of unified information management means, it depends more on personal skills and experience. On the other hand, discrete data files and 2D detection data can’t provide the staff with intuitive and stereoscopic visual effects, which affects the prediction and analysis of the staff to a certain extent. In view of the above problems, this paper deeply analyzes the characteristics of nuclear power NDT data, and proposes a 3D visualization method for ultrasonic defects of NPP reactor pressure vessel (RPV) based on digital twin. It also forms a 3D visualization digital twin system, which overlays and maps the 3D digital model of RPV with the reconstructed 3D defects, while providing the necessary 3D interaction. Through the research results of this paper, the digital and intelligent management methods of NDT data in NPP have been improved, and an outstanding 3D basis for prediction and analysis of NDT defects in NPP has been provided.
{"title":"Research and Application of 3d Visualization Digital Twin System for Ultrasonic Testing of Key Equipment in NPP","authors":"Zheng Yang, Yi Zhang, Hao Wang, Ya-nan Zhang","doi":"10.1115/icone29-91533","DOIUrl":"https://doi.org/10.1115/icone29-91533","url":null,"abstract":"\u0000 The internal conditions and surface defects of key equipment in nuclear power plant (NPP) are mainly detected though non-destructive testing (NDT) technology, which is the key basis for maintenance and diagnosis of nuclear power main equipment. At present, there are many types and huge quantities of NDT data. Due to the lack of unified information management means, it depends more on personal skills and experience. On the other hand, discrete data files and 2D detection data can’t provide the staff with intuitive and stereoscopic visual effects, which affects the prediction and analysis of the staff to a certain extent. In view of the above problems, this paper deeply analyzes the characteristics of nuclear power NDT data, and proposes a 3D visualization method for ultrasonic defects of NPP reactor pressure vessel (RPV) based on digital twin. It also forms a 3D visualization digital twin system, which overlays and maps the 3D digital model of RPV with the reconstructed 3D defects, while providing the necessary 3D interaction. Through the research results of this paper, the digital and intelligent management methods of NDT data in NPP have been improved, and an outstanding 3D basis for prediction and analysis of NDT defects in NPP has been provided.","PeriodicalId":422334,"journal":{"name":"Volume 12: Innovative and Smart Nuclear Power Plant Design","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125202094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Air pollution and the energy problem have become concerned and urgently needed to be solved all over the world in recent years. Coal-fired boilers in industrial parks are an important source of air pollutants. Low temperature heating reactor built in industrial zone is an ideal substitute for coal-fired boiler because of its excellent inherent safety and cleanliness. The new type nuclear heating reactor named NHR200-II was proposed by Institute of Nuclear and New Energy Technology of Tsinghua University in 2015[1]. Compared with the previous generation NHR200, the thermal parameters of NHR200-II are improved which can not only be used for regional heating but also realize the multi-purpose like power supply, steam supply and seawater desalination. And the economic benefits are also greatly improved. The design of NHR200-II is based on the design, construction and operation experience of NHR5 which has maintained running safely up to now and NHR200. The main technical features include three circuit design, integrated layout of primary circuit, full power natural circulation, and automatic self-pressurization. NHR200-II uses the traditional anti-seismic technology at present. However, the requirements of seismic performance of reactors have generally increased after Fukushima disaster. This paper tries to apply seismic isolation in NHR200-II to meet the improved requirements of seismic performance and realize the standardized design by which the magnitude of design ground motion is not restricted in the future. Base isolation, which means setting isolation devices like elastomeric bearings or spherical sliding bearings between the foundation and the superstructure, has been widely applied in normal buildings and bridges, but still needs particular design for nuclear reactors. This paper describes NHR200-II seismic isolation system, which consists of the foundation, raft, isolation layer and the whole nuclear island as superstructure. In addition, the paper also tells the design process of the system, including designing of the raft, selecting of isolators and their layout design based on the environment and mechanical property, etc. And the particular calculation method of the performance parameters and acceptance criteria are also shown in this paper. Finally, the overall design method of seismic isolation is given as a conclusion.
{"title":"Seismic Isolation Scheme Design of 200MW Nuclear Heating Reactor","authors":"Nannan Hou, Jianling Dong","doi":"10.1115/icone29-90555","DOIUrl":"https://doi.org/10.1115/icone29-90555","url":null,"abstract":"\u0000 Air pollution and the energy problem have become concerned and urgently needed to be solved all over the world in recent years. Coal-fired boilers in industrial parks are an important source of air pollutants. Low temperature heating reactor built in industrial zone is an ideal substitute for coal-fired boiler because of its excellent inherent safety and cleanliness. The new type nuclear heating reactor named NHR200-II was proposed by Institute of Nuclear and New Energy Technology of Tsinghua University in 2015[1]. Compared with the previous generation NHR200, the thermal parameters of NHR200-II are improved which can not only be used for regional heating but also realize the multi-purpose like power supply, steam supply and seawater desalination. And the economic benefits are also greatly improved. The design of NHR200-II is based on the design, construction and operation experience of NHR5 which has maintained running safely up to now and NHR200. The main technical features include three circuit design, integrated layout of primary circuit, full power natural circulation, and automatic self-pressurization.\u0000 NHR200-II uses the traditional anti-seismic technology at present. However, the requirements of seismic performance of reactors have generally increased after Fukushima disaster. This paper tries to apply seismic isolation in NHR200-II to meet the improved requirements of seismic performance and realize the standardized design by which the magnitude of design ground motion is not restricted in the future. Base isolation, which means setting isolation devices like elastomeric bearings or spherical sliding bearings between the foundation and the superstructure, has been widely applied in normal buildings and bridges, but still needs particular design for nuclear reactors.\u0000 This paper describes NHR200-II seismic isolation system, which consists of the foundation, raft, isolation layer and the whole nuclear island as superstructure. In addition, the paper also tells the design process of the system, including designing of the raft, selecting of isolators and their layout design based on the environment and mechanical property, etc. And the particular calculation method of the performance parameters and acceptance criteria are also shown in this paper. Finally, the overall design method of seismic isolation is given as a conclusion.","PeriodicalId":422334,"journal":{"name":"Volume 12: Innovative and Smart Nuclear Power Plant Design","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125367085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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