United States Nuclear Regulatory Commission - Protecting People and the Environment

Common Cause Failure Insights

Insights studies were performed on the set of common-cause failures (CCF) of emergency diesel generators, motor-operated valves, motor-driven pumps, and circuit breakers. The data studied were derived from the NRC CCF database, which is based on U.S. commercial nuclear reactor power plant data. These reports are the result of in-depth reviews of the CCF data for these components. The objective of these reports are to look beyond the CCF parameter estimates to gain further understanding of why CCF events occur and what measures may be taken to prevent, or at least mitigate the effect of these CCF events.

The insight studies are documented in "Common-Cause Failure Event Insights" (NUREG/CR-6819), Volumes 1 through 4. The links below provide the current information for the study and latest results.

Quantitative Results:

Insights Studies:

Insights Studies NUREG/CR-6819:

Page Last Reviewed/Updated Tuesday, December 8, 2020