"This criteria document provides guidelines for the designer in interpreting the requirements of Title 10@ Code of Federal Regulations@ Part 50@ ""Licensing of Production and Utilization Facilities@'' Appendix A@ ""General Design Criteria for Nuclear Power Plants@"" with respect to design against single failures in PWR fluid process systems.[1]2 Means of treating both active and passive failures are addressed for safety-related fluid process systems following various initiating events. Current acceptable practice is used as a basis for the criteria. Failure criteria for the electric power supply and control systems and the protection systems are provided in: IEEE-308-1974 ""IEEE Standard Criteria for Class 1E Power Systems for Nuclear Power Generating Stations@"" [ 2] IEEE- 279-1971 ""IEEE Standard Criteria for Protection Systems for Nuclear Power Generating Stations@"" (ANSI N42.7-1972) [3]; and IEEE- 379-1977 (Revision of IEEE-379-1972/ANSI N41.2) ""IEEE Standard for Application of the Single-Failure Criterion to Nuclear Power Generating Station Class 1E Systems."" [4] Structural failures of components@ such as braces@ supports@ or restraints@ as well as occurrences involving common mode failures@ are excluded. 2Numbers in brackets refer to corresponding numbers in Section 5@ References."