The application of the single-failure criterion to the electrical power, instrumentation, and control portions of nuclear power generating station safety systems is covered. Conformance with the requirements of IEEE Std 603-1991 and the single-failure criterion as stated in that document is established. Interpretation and guidance in the application of the single-failure criterion, a discussion of the failures, and an acceptable method of single-failure analysis are presented.

This document covers the application of the single-failure criterion to the electrical power, instrumentation, and control portions of nuclear power generating station safety systems. The purpose is to interpret and provide guidance in the application of the single failure criterion, discuss failures, and present an acceptable method of single-failure analysis. It is not the function of this standard to identify where the single-failure criterion is to be applied or to force compliance on any system; however, in those cases where the single-failure criterion has been invoked, this standard establishes the requirements for its application. This standard shall be used to establish conformance with the requirements of ANSI/IEEE Std 603-1980 [6] and the single-failure criterion as stated in that document.