Idaho National Laboratory has provided technical support to the U.S. Nuclear Regulatory Commission (NRC) since the 1980s in the areas of nuclear power plant reliability, probabilistic risk modeling, and operating experience (OpE) data analysis. The NRC OpE data analysis program produces key reliability and risk parameters that are used in the NRC’s Standardized Plant Analysis Risk models, including component failure rates and unavailabilities, initiating event frequencies, and common-cause failure (CCF) parameter estimates (https://nrcoe.inl.gov/). These data products are also widely used by the nuclear industry as generic inputs for plant-specific probabilistic risk assessment (PRA) models.

NUREG/CR-6823, Handbook of Parameter Estimation for Probabilistic Risk Assessment, commonly referred to as the HOPE manual, provides guidance on the sources of information and statistical methods used to estimate PRA parameters and quantify associated uncertainties. Together with related guidance documents, such as NUREG/CR-5845 for CCF modeling, the HOPE manual forms a methodological foundation for the NRC OpE data analysis program.

This presentation provides an overview of the NRC OpE data analysis program, the role of the HOPE manual in supporting parameter estimation for PRA applications, and ongoing efforts to update and enhance the manual to reflect current data sources, analytical methods, and risk-informed regulatory needs.