Dismantling of nuclear power plants at optimal NPV

Today, worldwide far more than 100 nuclear power plants, which have been decommissioned in the recent years, are waiting for their complete dismantling. Since the dismantling of a single reactor causes costs of up to one billion Euros and lasts up to 15 years, the elaboration of a scheduling approach helping to optimize the net present value of a dismantling project seems to be worthwhile. In this paper we present a resource-constrained project scheduling approach optimizing the total discounted disbursements of dismantling a nuclear power plant. For the corresponding NP-hard optimization problem, we introduce an appropriate project scheduling model with minimum and maximum time lags, renewable and cumulative resources as well as multiple execution modes. To solve this model, we introduce a relaxation-based enumeration approach that delivers optimal solutions for problem instances containing up to 50 activities.