From the perspective of resource management and the circular economy, the FCC is more than a physics instrument: it is an opportunity to demonstrate, how a major European infrastructure can be built while turning one of its environmental liabilities, excavated materials, into a resource. Today, reuse rates for excavated and construction materials in Europe are only around 30%, largely because conventional laboratory characterisation takes days and prevents on-site decisions (Hale et al., Sustainability 13(11), 6083, 2021).

Within the Horizon Europe project iRIS, MUL and its partners are developing AI-supported real-time characterisation of excavated materials and processes to reconstitute functional soil from excavation and demolition streams. These technologies are being piloted with sample materials from CERN and from Einstein Telescope candidate sites, with the explicit aim of being available for FCC construction. Studies indicate that circular management of FCC excavation materials could reduce related costs substantially while restoring degraded land and creating skills, jobs and transferable know-how for the wider construction and recycling sectors. We therefore consider the FCC, if realised with such an approach, a credible driver of the circular economy in the region and in Europe, and we recommend that circular-economy be anchored in the project from the design stage.