System Design Analysis for Replacement of U.S. Coal Power Plants with Small Nuclear Reactors

Coal power plants are the predominant energy generation technology in many countries. A variety of policy and economic pressures are driving the replacement of this legacy technology, but the electricity generated by retiring coal power plants must be replaced and the generation capacity increased to meet projected demand growth. A diversity of alternatives to coal generation, including nuclear power, are key components of nearly every study of a future sustainable electricity sector. At present, small modular nuclear reactors (SMR) have been proposed and planned by researchers, utilities, and governments to enable on-site replacement of existing coal power generators. By directly replacing coal power plants with SMRs, these programs seek to develop zero-emissions, high-reliability electricity generation at lower cost than possible in green-field developments. To assess the role proposed coal-to-nuclear conversions could play in adoption of SMRs, an improved understanding of the value of existing infrastructure at coal power sites is needed. Consequently, the present investigation assesses the economic value associated with retaining the grid interconnection and cooling water at potential coal-to-nuclear sites across the United States. Results indicate that, when installing a single 300 MW reactor at one site, use of the existing cooling method and water source can save $6.8M - $23.5M annually depending on the cooling method chosen at the new site, with expected savings of $13.3M. Across the entire fleet potential expected savings are $1.7B - $4.5B annually, depending on the number of reactors installed. Similarly, the value of existing electrical grid interconnection at a single site can range from $25M to $53.6M, with interconnections across the fleet valued from $5.3B – $10.1B. These findings suggest that grid interconnection and cooling water availability at coal power sites represent economic value that should be considered, along with other factors, by entities evaluating siting alternatives for SMR installations.