The relative competitiveness of nuclear and coal plants is assessed by dividing the U.S. into 21 regions and using a computer model to calculate costs for each plant in each region. Scenarios were considered in which resource depletion and environmental considerations affect coal generation costs. Analysis shows that if coal prices are constant in real terms and if SO2 scrubbers are not required, nuclear plants produce electricity less expensively than coal plants in 45% of the country (adjusted for generation size). When either coal prices rise in real terms or when scrubbers are required, nuclear plants have the advantage in more than 90% of the market. In addition, sensitivity studies show that uncertainties in forecasting uranium and coal prices produce the largest difficulty in accurately comparing nuclear and coal electrical generation costs.