WG_6.3 - Safety Systems and Single-Failure Criteria Working Group

Francis Novak

Minimum functional and design criteria for the power, instrumentation, and control portions of nuclear power generating station safety systems are established. The criteria are to be applied to those systems required to protect the public health and safety by functioning to mitigate the consequences of design basis events. The intent is to promote appropriate practices for design and evaluation of safety system performance and reliability. Although the standard is limited to safety systems, many of the principles may have applicability to equipment provided for safe shutdown, post accident monitoring display instrumentation, preventive interlock features, or any other systems, structures, or equipment related to safety.

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.

Minimum functional and design criteria for the power, instrumentation, and control portions of nuclear power generating station safety systems are established in this standard. The criteria are to be applied to those systems required to protect the public health and safety by functioning to mitigate the consequences of design basis events. The intent is to promote appropriate practices for design and evaluation of safety system performance and reliability. Although the standard is limited to safety systems, many of the principles may have applicability to equipment provided for safe shutdown, post accident monitoring display instrumentation, preventive interlock features, or any other systems, structures, or equipment related to safety.