Abstract

The design philosophy of defence in depth for nuclear power plant establishes in consideration of technical, artificial and organizational management failures. Defence in depth principle is a safety design idea that runs through all stages of production activities in the whole life of nuclear power plants. Each of defence lines must be reliable and independent of each other as much as possible. According to the system function and operation requirements of nuclear power plants, this paper analyses latest requirements of defence in depth and diversity line of nuclear power plants, based on the research and analysis of laws and regulations, standard and good practices at domestic and abroad. According to the requirements of independence, common cause fault and diversity, the independence and diversity of defence line in depth of instrument and control systems are analyzed, the weak points of common cause fault of defence line in depth of instrument and control system are identified, and the improved analysis method and improved realization steps are put forward. And then each of its lines of defence provided diversity for common cause failure. This paper discusses the types of common cause faults and typical countermeasures of defence in depth and diversity line for digital instrument and control system. This paper summarizes the common cause failure analysis methods, processes and countermeasures for digital instrument and control systems in nuclear power plant.

This content is only available via PDF.
You do not currently have access to this content.