Design And Application Of Nuclear Safety DCS Application Software V&V

Nuclear power,as a kind of clean energy,its safety issues are increasingly attracting attention at home and abroad with its rapid development.The I&C system is the central nervous system of nuclear power plant,especially the safety I&C system,which plays a crucial role in ensuring the safe operation of nuclear power plant.With the rapid development of computer technology,computer-based digital control system(DCS)has gradually replaced the analog I&C system.The most important characteristic of safety DCS system is to realize the safety protection function of nuclear power plant by software.How to ensure that the software development process and the final product meet the expected requirements without introducing unexpected features is the key to ensure the reliability and security of safety DCS system.Software V&V technology,as an important means to ensure the quality and reliability of safe DCS software,is an indispensable activity in the software development process of safety DCS system,and has been highly concerned by national regulators and users.Therefore,the research on software V&V technology is of great significance.The software contained in the safety DCS system of nuclear power plant can be divided into platform software and application software according to its functions.Platform software refers to system software,algorithm block software,engineering application software development tools,etc.Application software refers to the software developed on the safe DCS system platform to meet the functional requirements based on the operation requirements of nuclear power plants.Safety DCS application software V&V activities are carried out synchronously with the application software development process throughout the entire life cycle.This paper will sort out the relevant domestic and foreign standards and regulations of nuclear power,such as HAF,HAD,IEC series standards,IEEE series standards,etc.,clarify the requirements of software V&V activities,establish the software V&V standards architecture,and determine the main standards to be followed in the implementation of software V&V activities.Furthermore,it further analyzes the standards followed by software V&V activities,and identifies the technical key points of software V&V activities,such as V&V independence,software integrity level,V&V process control etc.,which lays a foundation for the design and application of the following application software V&V activity scheme.In addition,this paper adopts safety DCS supply project of Yangjiang nuclear power plant Unit5 as an engineering example,and combines the technical key points of software V&V to design the safety DCS application software V&V scheme,such as V&V independence scheme,software integrity level scheme,V&V process control scheme,etc.,and apply them in the project to ensure that the application software V&V scheme and activity execution meet the relevant requirements of standard and regulations.Through practice,the software V&V activity found and solved a large number of application software anomalies in the process of development of safety DCS application software,effectively improved the quality of DCS system application software,and achieved good application effect,and safety DCS application software V&V activities have successfully passed the national regulators and the purchaser's strict censorship.This V&V scheme has also been promoted and applied in subsequent DCS supply projects,such as Tianwan nuclear power plant Unit 5&6,Hongyanhe nuclear power plant Unit 5&6,Fangchenggang nuclear power plant Unit 3&4 etc.