Predicting nuclear plant capacity factors

Frequent or long outages can dramatically hike the per-kilowatt cost of nuclear power plants. But high capacity factors can also improve plant economics by spreading fixed costs over more kilowatt-hours. That's why it's so important for both plant owners and regulators to predict nuclear plant performance; to know what's normal and what's not. Utility analysts have been studying nuclear power plant performance for almost two decades. At Komanoff Energy Associates (KEA) we have assembled a nuclear plant database that spans 26 years of operating experience (1968 through 1993). It covers 111 U.S. nuclear plants, including every full calendar-year of commercial operation by reactors 400 megawatts (MW) or larger, totalling 1,566 reactor-years. To develop our model for predicting nuclear capacity factors, we tested a number of regression formulas, each correlating annual capacity factors with a set of industrywide and plant-specific characteristics.