The reliability and availability of the reactor protection system （RPS） can be improved by using M out of N judg- ment system. By analyzing two quantitative indicators, the rate of refusal to operate and mal-operati...The reliability and availability of the reactor protection system （RPS） can be improved by using M out of N judg- ment system. By analyzing two quantitative indicators, the rate of refusal to operate and mal-operation rate, a strict math- ematical formula and an approximate calculation are stated. The differences of a series of judgment systems are discussed on condition that the unsafe failure probability and the security failure probability are both 0.1. Based on given parameters （A, B,P, Q）： A is upper limit of the refusal rate for the RPS, B is upper limit of the real-operation rate, P and Q are basic protection unit rates corresponding to refusal rate and mal-operation rate, respectively. According to these parameters, the values of N and M can be solved.展开更多
Destructions at Fukushima Daiichi NPP （nuclear power plant） caused by earthquake have shown that design level of seismic influences on the equipment has been exceeded. The accident demonstrated the need for stricter...Destructions at Fukushima Daiichi NPP （nuclear power plant） caused by earthquake have shown that design level of seismic influences on the equipment has been exceeded. The accident demonstrated the need for stricter regulations to ensure the seismic resistance of NPP and the need to develop and implement additional anti-seismic procedures in the course of their operation. To proof seismic reliability of NPP systems and components must be made special studies of logarithmic decrement of systems NPP and components. The correct definition of coolant thermodynamics parameters and acoustic parameters are necessary to evaluate logarithmic decrement of coolant systems NPP and their components and consequently for providing of NPP seismic reliability. The proof of presence of a gas phase in the coolant inside reactor is of great importance for practice because of its influence on coolant acoustical parameters and consequently on range of frequency of seismic-acoustical resonance type interaction. Results are obtained by using of known methods in oscillation theory, general acoustics, thermodynamic, electro-mechanical analogies. As well as using experimental data obtained from the vibration dynamical controls reactor WWER-1000.展开更多
In this paper,the network reliability of an actual digital instrument and control system (DICS) network is analyzed by using GO-FLOW methodology (GFM).The evaluations of common-cause failure (CCF) and uncertainty are ...In this paper,the network reliability of an actual digital instrument and control system (DICS) network is analyzed by using GO-FLOW methodology (GFM).The evaluations of common-cause failure (CCF) and uncertainty are incorporated.Three significant CCF groups (real time servers,gateways,reactor protection system) and three typical time intervals (10 min,1 h,and 24 h) are selected in the analysis.It is concluded that the network contribution of CCF accounts for over 68% of the system failure probability.The result indicates that GFM is suitable for the network reliability analysis.展开更多
基金Research Project of Hunan Province Education Department(No.14C0972)
文摘The reliability and availability of the reactor protection system （RPS） can be improved by using M out of N judg- ment system. By analyzing two quantitative indicators, the rate of refusal to operate and mal-operation rate, a strict math- ematical formula and an approximate calculation are stated. The differences of a series of judgment systems are discussed on condition that the unsafe failure probability and the security failure probability are both 0.1. Based on given parameters （A, B,P, Q）： A is upper limit of the refusal rate for the RPS, B is upper limit of the real-operation rate, P and Q are basic protection unit rates corresponding to refusal rate and mal-operation rate, respectively. According to these parameters, the values of N and M can be solved.
文摘Destructions at Fukushima Daiichi NPP （nuclear power plant） caused by earthquake have shown that design level of seismic influences on the equipment has been exceeded. The accident demonstrated the need for stricter regulations to ensure the seismic resistance of NPP and the need to develop and implement additional anti-seismic procedures in the course of their operation. To proof seismic reliability of NPP systems and components must be made special studies of logarithmic decrement of systems NPP and components. The correct definition of coolant thermodynamics parameters and acoustic parameters are necessary to evaluate logarithmic decrement of coolant systems NPP and their components and consequently for providing of NPP seismic reliability. The proof of presence of a gas phase in the coolant inside reactor is of great importance for practice because of its influence on coolant acoustical parameters and consequently on range of frequency of seismic-acoustical resonance type interaction. Results are obtained by using of known methods in oscillation theory, general acoustics, thermodynamic, electro-mechanical analogies. As well as using experimental data obtained from the vibration dynamical controls reactor WWER-1000.
基金Supported by Nuclear Safety Research Association and Tohoku University for Nuclear Researchers Exchange Program 2010National High Technology and Development Program ("863"Program)of China(No.2007AA041009)
文摘In this paper,the network reliability of an actual digital instrument and control system (DICS) network is analyzed by using GO-FLOW methodology (GFM).The evaluations of common-cause failure (CCF) and uncertainty are incorporated.Three significant CCF groups (real time servers,gateways,reactor protection system) and three typical time intervals (10 min,1 h,and 24 h) are selected in the analysis.It is concluded that the network contribution of CCF accounts for over 68% of the system failure probability.The result indicates that GFM is suitable for the network reliability analysis.
