On-site power system reliability of a nuclear power plant after the earthquake

Kerntechnik ◽  
2013 ◽  
Vol 78 (2) ◽  
pp. 99-112 ◽  
Author(s):  
A. Volkanovski
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Power System ◽  
System Reliability ◽  
Nuclear Power ◽  
Power System Reliability

The Necessity of Independent Configuration of the DC Power Supply System Used for Power Supply and Auxiliary Power Supply in Nuclear Power Plant

2018 ◽  
Author(s):  
Zhang Zhichao
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Power System ◽  
Power Supply ◽  
Nuclear Power ◽  
Power Supply System ◽  
Power Source ◽  
Dc Power ◽  
Auxiliary Power ◽  
Ac Power

At present, in the typical design of China’s nuclear power plant, main generation system is connected to the power grid by 500 kV system. 500 kV system as a priority power source, 220kV system as an auxiliary power source. Independent operation of 500kV and 220kV system, improved the reliability of power supply of nuclear power plant. However, the DC 220V power system used to control the 500kV and 220kV system in the switch station of partial nuclear power project is not independently configured, and the design form of one set of DC system is used in the transformer station. In recent years, there are many accidents that AC power enters into the DC power system, resulted in the loss of power source in the transformer station. The loss of external power source in the whole plant is very significant. In this paper, the influence of AC power entering into DC power system on relay protection device is analyzed, the measures to prevent the AC power into DC power system are discussed, the necessity of independent configuration of DC control power system for the 500kV priority power system and 220kV auxiliary power supply system is analyzed.

Modeling and Simulation of Nuclear Power Units for Primary Frequency Regulation Research

2013 ◽  
Author(s):  
Zhenpeng Tang ◽  
Fuyu Zhao ◽  
Pengfei Wang ◽  
Li Chen ◽  
Huawei Fang
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Power System ◽  
Nuclear Power ◽  
Frequency Stability ◽  
Control Mode ◽  
Frequency Regulation ◽  
Pressurized Water ◽  
Matlab Simulink ◽  
Primary Frequency

The power system frequency stability problem has been the focus of attention since 1920s. Primary frequency regulation (PFR) is one of vital methods to maintain frequency stability, especially when the power system suffers a sudden load disturbance, such as the substation tripping or generator outage accident. To a power system, the more power units participating in PFR, the frequency stability will be controlled better. With the rapid development of nuclear power units in China, the study of the nuclear power units participating in PFR of power system has becoming a pressing problem. In the present study, a detailed nonlinear dynamic mathematical model of the whole pressurized water reactor (PWR) nuclear power plant is built. The dynamic calculation codes are compiled to dynamic link library (DLL) files, which are developed by using FORTRAN language, and the compiled DLL files are embedded into MATLAB/SIMULINK simulation platform by using S-function, the control systems are designed and the whole system of PWR nuclear power plant is simulated in MATLAB/SIMULINK finally. In this method, the operation and control mode of PWR participating in PFR of power system is analyzed and simulated. The simulations results show that the PWR nuclear units are feasible in participating in PFR from safety and economy.

Reliability of PCCS in AP1000 Based on Accident Development

2016 ◽  
Author(s):  
Yu Yu ◽  
Shengfei Wang ◽  
Fenglei Niu
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Physical Process ◽  
System Reliability ◽  
Nuclear Power ◽  
Cooling System ◽  
Natural Circulation ◽  
System Structure ◽  
System Failure ◽  
Process Failure

Passive containment cooling system (PCCS) is an important safety-related system in AP1000 nuclear power plant, by which heat produced in reactor is transferred to the heat sink – atmosphere – based on natural circulation, independent of human response or the operation of outside equipments, so the reactor capacity of resisting external hazards (earthquake, flood, etc.) is improved. However since the system operation based on natural circulation, many uncertainty factors such as temperatures of cold and heat sources will affect the system reliability, and physical process failure becomes one of the important contributors to system failure, which is not considered in the active system reliability analysis. That is, the system will lose its function since the natural circulation cannot be established or kept even when the equipments in the system can work well. The function of PCCS in AP1000 is to transfer the heat produced in the containment to the environment and to keep the pressure in the containment below its threshold. After accidents the steam is injected to the containment and can be cooled and condensed when it arrives at the containment wall, then the heat is transferred to the atmosphere through the steel vessel. So the peak value of the pressure is influenced by the steam situation which is injected into the containment and the heat transfer and condensate processes under the accidents. In this paper the dynamic thermal-hydraulic (T-H) model simulating the fluid performance in the containment is established, based on which the system reliability model is built. Here the total pressure in the containment is used as the success criteria. Apparently the system physical process failure may be related to the system working state, the outside conditions, the system structure parameters and so on, and it’s a heavy work to analyze the influences of all the factors, so only the effects of important ones are included in the model. Monte Carlo (MC) simulation is used to evaluate the system reliability, in which the input parameters such as air temperature are sampled based on their probabilistic density distributions. The pressure curves along with the accident development are gained and the system reliabilities under different accidents are gotten as well as the main contributors. The results illustrate that the system physical process failure probabilities are varied under different climate conditions, which result in the system reliability and the main contributors to system failure changing, so the different methods can be taken to improve the system reliability according to the local condition of the nuclear power plant.

A Research Summary on Combined Peaking Load Strategies of Nuclear Power Plant

2014 ◽  
Vol 986-987 ◽  
pp. 196-201 ◽  
Author(s):  
Tao Zhang ◽  
Xiao Dong Ma ◽  
Yu Zhu ◽  
Gang Wang ◽  
Peng Ye
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Power System ◽  
Nuclear Power ◽  
Technology Development ◽  
Peak Load ◽  
Development Trend ◽  
Storage Unit ◽  
Energy Storage Unit ◽  
Load Regulation

Based on extensive research, introduced the peak load regulation characteristics and capacity of different nuclear power plant (NPP) in this paper. The running mode of NPP participating in peak load regulation of power system, combined operation tactics of NPP with other peaking power source and synergistic scheduling of an integrated power generation system with wind, photovoltaic, energy storage unit and NPP were summarized, technology development trend of NPP participating in peak load regulation of power system was analyzed and forecasted.

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