We studied how crushed salt changes over time so that it can safely seal a future waste repository. By combining new laboratory tests with improved computer models, we created a clearer picture of how the material compacts and when it becomes tight. Our results reduce uncertainty in long‑term predictions and support safer planning for storing radioactive waste underground.

Pretreatment of radioactive waste by partitioning and transmutation (P&T) in accelerator-driven systems (ADSs) has been mentioned as an approach to significantly reduce the requirements and risks associated with a – still necessary – final repository for decades. We show that the technological concept is still very much the same as the one proposed decades ago and discuss possible additional revenue from radioisotope production in transmutation facilities.