Selection of projects’ primary and secondary mitigation actions through optimization methods in nuclear decommissioning projects

Abstract

The growing interest in nuclear power has brought attention back to the general condition of nuclear power plants. In fact, according to the main intergovernmental organisations responsible for nuclear energy, more than 150 basic nuclear facilities (in-service reactors, downgraded reactors, fuel fabrication plants, reprocessing plants, and waste storage areas) should be seriously checked for safety reasons, while many others are close to the end of their lifecycles (lasting generally around 50–60 years) – thus, there is an urgent need for research into the management of Nuclear Decommissioning Projects (NDPs). In particular, the high complexity of these projects makes it fundamental to implement strong risk management procedures, aimed at identifying and analyzing all possible hazards, and finding and implementing the appropriate risk response actions. This paper focuses on the selection of mitigation actions and proposes optimizationisation algorithms to select the most time-effective set of risk responses for a nuclear decommissioning project. A single case study of an Italian completed NDP was employed to investigate the application of optimization techniques in the mitigation action selection phase, considering also secondary risks and secondary mitigation action. The results show that the performance that would have been achieved through the optimization algorithm would have been superior, both from the point of view of a reduced time delay, and in terms of a more effective balance between overall risk coverage and implementation costs.