During the next decade, most states in the USA will deregulate electricity generation. Nuclear power plants that were ordered and built in a regulated environment will continue to be regulated as nuclear facilities. However, under state deregulation the price they receive for their electricity will be set largely in non-regulated markets. This paper examines the competitiveness of the nuclear power industry with a probabilistic model to identify which nuclear power units face the highest risk of early retirement under deregulation. Projected outputs under both average-cost and marginal-cost pricing are compared with expected generation under continued rate-of-return regulation. Nuclear units at risk of early retirement are in regions with the lowest forecast prices or are old plants. But, if CO, regulation targets an emission reduction to 9% below projected 2010 levels (projected to be 24% above 1990 levels), there are only a few units at risk of early retirement after 2015.