Using Expert Judgments to Estimate the Multipliers of Performance Shaping Factors in Digital Main Control Rooms of Nuclear Power Plants

The lack of human performance data in human reliability analysis (HRA) has been lamented in the literature for a long time. It can increase the variability, uncertainty, unreliability of HRA outcomes to probabilistic risk analysis (PRA). This situation is even worse for PRA/HRA in digital main control rooms (MCRs) of nuclear power plants (NPPs). Expert judgment is used when data is unavailable. This study applied two expert judgment techniques, absolute probability judgment (APJ) and ratio magnitude estimation (RME), to generate licensed operators’ judgments on the multipliers of performance shaping factors (PSFs) in digital MCRs. It is found that the PSF multipliers by APJ and RME are highly convergent with each other and have similar numerical values. Taking Time Pressure PSF for example, its multipliers were found to be also consistent with those from other data sources. This study may show the usefulness of expert judgments for producing PSF multipliers in digital MCRs.