Spent Fuel Pool Human Reliability Analysis (HRA), Draft for Comment

One of the key issues that has emerged in performing a probabilistic risk assessment (PRA) for the spent fuel pool during the decommissioning phase of a nuclear power plant's lifecycle is how much credit can be given to the operating staff to respond to an incident that impacts the spent fuel pool that would, if not attended to, lead to a loss of cooling of the spent fuel and eventually to a zirconium fire. The initial risk assessment performed by the staff used estimates of human error probabilities that resulted in operator non-response being a significant contribution to the estimates of risk. The industry expressed its concern that, because of the very long time scales (typically, tens of hours) and the relative simplicity of the required actions compared with those needed to control nuclear power reactor transients, the non-response probabilities should be very low, and, in particular, much lower than those assumed in the staff analysis.