scope:

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.

Purpose

The purpose of this document is to interpret and provide guidance in the application of the single-failure criterion, discuss the 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 IEEE Std 603-1991 ¹ and the single-failure criterion as stated in that document.

NOTE-The single-failure criterion is also applied to designated safety functions in other standards, for example, IEEE Std 308-1991, ANSI/ANS 51.1-1983 (Reaff 1988), and ANSI/ANS 52.1-1983 (Reaff 1988). Application of the singlefailure criterion to the aggregate of all plant structures, systems, and components is specified in 3.2.1 of ANSI/ANS 51.1-1983 (Reaff 1988), ANSI/ANS 52.1-1983 (Reaff 1988), and [B3]. ²

¹ Information on references can be found in clause 2.

² The numbers in brackets, when preceded by the letter B, correspond to the bibliographical items listed in clause 7