CCF Parameter Estimates

Quantitative results of the common-cause failure (CCF) data collection effort are presented for the current data set.

Equipment failures that contribute to CCF events are identified during searches of Licensee Event Reports (LER), Nuclear Plant Reliability Data System (NPRDS) failure reports, and Equipment Performance and Information Exchange (EPIX) failure reports.

The quantitative results are presented as both alpha factors and multiple Greek letter parameter estimations. The alpha factor distributions are also presented.

Same as the Industry Average Parameter Estimates 2020 Update, the CCF Parameter Estimations 2020 Update also used the most recent 15-year period data so that the analysis results could reflect the most recent industry performance yet still provide sufficient data.

Current Results:

Supporting Information:

Historical Results:

Page Last Reviewed/Updated Monday, May 16, 2022