Abstract Most part of nuclear power sites around the world have multiple reactors, requiring different approaches to deal with plants interdependencies during its decommissioning. Usually, decommissioning strategies are proposed based on previous experiences. A strategy that would organize the decommissioning process is often proposed based on previous experience of similar projects. Different management tools for decommissioning cost estimation are found in literature but none of them focus on strategy proposal, which considers in a properly way plants interdependencies as well as mathematical models for costing the process. To overcome of these difficulties, the present work presents a method for decommissioning strategy proposal which could be used integrated with a mathematical model for cost estimation. Five strategies were obtained with the proposed method. The cost to decommissioning a case study site and its plants is also provided considering the Brazilian context.