Criticality and sensitivity/uncertainty analysis of spent nuclear fuel dry casks

Dry storage systems are considered worldwide as the main solution to store spent nuclear fuel outside the spent fuel pools of nuclear power plants. In these storage systems, re-criticality conditions must be avoided during the storage and transport of spent nuclear fuel. In this work, it has been found out that only for PWR casks re-criticality conditions can happen, under realistic conditions in case of cask internal flooding with natural water, while for BWR casks it has not been found out, under realistic conditions. Therefore, this work reports the criticality and sensitivity/uncertainty analysis of these systems carried out within the EU EURAD project, proposing some solutions to improve the safety levels.