Taxonomy for Common-Cause Failure Vulnerability and Mitigation

Wood, Richard Thomas¹  Korsah, Kofi¹  Mullens, James Allen¹  Pullum, Laura L.¹ 

[1]Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

关键词: NUCLEAR POWER PLANTS;    MITIGATION;    TAXONOMY;    VULNERABILITY;    FAILURES;    CLASSIFICATION;    COST;    DESIGN;    REACTOR INSTRUMENTATION;    REACTOR CONTROL SYSTEMS;    ON-LINE SYSTEMS;    REACTOR ACCIDENTS;   

DOI  :  10.2172/1252139
RP-ID  :  ORNL/SPR--2015/209
PID  :  OSTI ID: 1252139
Others  :  Other: NT0107000
Others  :  NENT011
Others  :  TRN: US1601353

美国|英语

来源: SciTech Connect

【 摘 要 】

Applying current guidance and practices for common-cause failure (CCF) mitigation to digital instrumentation and control (I&C) systems has proven problematic, and the regulatory environment has been unpredictable. The potential for CCF vulnerability inhibits I&C modernization, thereby challenging the long-term sustainability of existing plants. For new plants and advanced reactor concepts, concern about CCF vulnerability in highly integrated digital I&C systems imposes a design burden that results in higher costs and increased complexity. The regulatory uncertainty in determining which mitigation strategies will be acceptable (e.g., what diversity is needed and how much is sufficient) drives designers to adopt complicated, costly solutions devised for existing plants. To address the conditions that constrain the transition to digital I&C technology by the US nuclear industry, crosscutting research is needed to resolve uncertainty, demonstrate necessary characteristics, and establish an objective basis for qualification of digital technology for nuclear power plant (NPP) I&C applications. To fulfill this research need, Oak Ridge National Laboratory is investigating mitigation of CCF vulnerability for nuclear-qualified applications. The outcome of this research is expected to contribute to a fundamentally sound, comprehensive basis to qualify digital technology for nuclear power applications. This report documents the development of a CCF taxonomy. The basis for the CCF taxonomy was generated by determining consistent terminology and establishing a classification approach. The terminology is based on definitions from standards, guides, and relevant nuclear power industry technical reports. The classification approach is derived from identified classification schemes focused on I&C systems and key characteristics, including failure modes. The CCF taxonomy provides the basis for a systematic organization of key systems aspects relevant to analyzing the potential for CCF vulnerability and the suitability of mitigation techniques. Development of an effective CCF taxonomy will help to provide a framework for establishing the objective analysis and assessment capabilities desired to facilitate rigorous identification of fault types and triggers that are the fundamental elements of CCF.