New Technologies for Safeguarding Spent Fuel Storage Facilities

In the process of Germany's ongoing energy transformation, fourteen of seventeen operating nuclear reactors have been gradually shut down since 2011. Germany’s plan is to completely phase out the nuclear power production. The defueling of the nuclear reactors leads to an overall inventory of more than spent fuel 1,000 casks, which will be stored in dry spent fuel storage facilities (SFSFs) until a disposal for high active waste will be available the earliest in 2050. Keeping Continuity of Knowledge (CoK) of the spent fuel stored in the SFSFs for the upcoming decades is a cornerstone of safeguards. The paper presents the state of the art of current safeguards technologies and the investigation of new techniques, which could be used in future to optimize safeguards of SFSFs. Due to the densely arranged casks in a storage configuration with limited space, verification of seals becomes more challenging and time consuming for inspectors with increasing storage occupancy. Technical solutions, which allow a short inspection time per cask with the ability of less frequent seal replacement or maintenance in the vicinity of spent fuel casks, would be advantageous. This could be achieved by using a laser curtain for containment and tracking (LCCT) without the physical presence of inspectors so that radiation exposure of inspectors and the accompanying operator’s staff can be avoided. As a suitable method for the automatic tracking of cask movements the field trial for testing the LCCT method will be presented. Moreover, a precise non-destructive method for a (re)-verification of spent fuel (SF) assemblies enclosed in thick-walled strongly shielding casks would be a benefit and a further advancement for safeguarding in the unlikely event that all safeguards-related containment and surveillance measures fail. As an applicable method muon tomography has to be discussed.