The basic principles that are needed to conduct a reliability analysis of safety systems are provided for designers and operators of nuclear power plant safety systems and the concerned regulatory groups. By applying the principles given, systems may be analyzed, results may be compared with reliability objectives, and the basis for decisions may be suitably documented. The quantitative principles are applicable to the analysis of the effects of component failures on safety system reliability. Although they have their greatest value during the design phase, the principles are applicable during any phase of the systemÕs lifetime. They may also be applied during the preoperational phase or at any time during the normal lifetime of a system.

This guide was prepared to provide the designers and operators of nuclear power plant safety systems and the concerned regulatory groups with the essential methods and procedures of reliability engineering that are applicable to such systems. By applying the principles given, systems may be analyzed, results may be compared with reliability objectives, and the basis for decisions may be suitably documented. The quantitative principles are applicable to the analysis of the effects of component failures on safety system reliability. The principles are applicable during any phase of the system's lifetime. They have their greatest value during the design phase. During this phase, reliability engineering can make the greatest contribution toward enhancing safety. These principles may also be applied during the preoperational phase or at any time during the normal lifetime of a system. When the principles are applied during either of these two phases, they will aid in the evaluation of syste...