核电技术是一门综合性的高级技术。核电站与常规电站的主要区别除了核电站本身建造的复杂性和高难度外,它对安全性和可靠性的要求甚高。因而,核电站的建造就围绕着核反应堆,对其各个运行和安全系统的组成设备有着极高的质量要求。尤其是近年来的三哩岛和切尔诺贝利核事故之后,世界各国对核电站的安全性和可靠性较之以前更为注重。鉴于核电站的这种特殊性,对其有关安全系统的组成设备及非安全系统的组成设备进行安全等级的划分和相应的质量级别的分类就显得非常的重要。这里仅简单概述国 Nuclear power technology is a comprehensive advanced technology. The main differences between nuclear power plants and conventional power plants In addition to the complexity and difficulty of constructing a nuclear power plant itself, its safety and reliability requirements are very high. As a result, the construction of a nuclear power plant revolves around nuclear reactors and places a high quality requirement on the components of its various operational and safety systems. Especially in recent years, after the Three Mile Island and Chernobyl nuclear accidents, the safety and reliability of nuclear power plants around the world have paid more attention than ever before. In view of the particularity of nuclear power plants, it is very important to classify the safety levels and the corresponding quality levels of the components of their safety systems and the non-safety systems. Here is a brief overview of the country