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Accelerator-based techniques are considered among the leading methods to produce radioactive nuclei. The ISOLDE facility (Isotope mass Separator On-Line DEvice) at the European Organization for Nuclear Research (CERN) is a unique source of beams of radioactive nuclides that are used in a wide range of research domains, from nuclear astrophysics to life sciences. Over 400 ISOLDE targets are currently stored at CERN and an average of 30 targets are irradiated every year. All these targets are planned to be dismantled and disposed of as radioactive waste in a dedicated repository in Switzerland. This paper provides an overview of the challenges related to the radionuclide activity predictions, the number of activation scenarios, dismantling and conditioning of the Radioactive Waste (RW) using a hot cell (HC), the high dose rate, uncertainties related to unknown geometry parameters of the RW packages, and finally industrializing a complex RW elimination process as ITEP for an accelerator complex. The performed work addresses each of these challenges and offers technical solutions based on state-of-the-art computational codes, statistical techniques, and state of art Non-Destructive Assay (NDA) techniques using high energy-resolution gamma spectrometry. The methodology followed can be of guidance for the development of similar processes at other facilities.

The CERN-MEDICIS (MEDical Isotopes Collected from ISolde) facility has delivered its first radioactive ion beam at CERN (Switzerland) in December 2017 to support the research and development in nuclear medicine using non-conventional radionuclides. Since then, fourteen institutes, including CERN, have joined the collaboration to drive the scientific program of this unique installation and evaluate the needs of the community to improve the research in imaging, diagnostics, radiation therapy and personalized medicine. The facility has been built as an extension of the ISOLDE (Isotope Separator On Line DEvice) facility at CERN. Handling of open radioisotope sources is made possible thanks to its Radiological Controlled Area and laboratory. Targets are being irradiated by the 1.4 GeV proton beam delivered by the CERN Proton Synchrotron Booster (PSB) on a station placed between the High Resolution Separator (HRS) ISOLDE target station and its beam dump. Irradiated target materials are also received from external institutes to undergo mass separation at CERN-MEDICIS. All targets are handled via a remote handling system and exploited on a dedicated isotope separator beamline. To allow for the release and collection of a specific radionuclide of medical interest, each target is heated to temperatures of up to 2,300°C. The created ions are extracted and accelerated to an energy up to 60 kV, and the beam steered through an off-line sector field magnet mass separator. This is followed by the extraction of the radionuclide of interest through mass separation and its subsequent implantation into a collection foil. In addition, the MELISSA (MEDICIS Laser Ion Source Setup At CERN) laser laboratory, in service since April 2019, helps to increase the separation efficiency and the selectivity. After collection, the implanted radionuclides are dispatched to the biomedical research centers, participating in the CERN-MEDICIS collaboration, for Research & Development in imaging or treatment. Since its commissioning, the CERN-MEDICIS facility has provided its partner institutes with non-conventional medical radionuclides such as Tb-149, Tb-152, Tb-155, Sm-153, Tm-165, Tm-167, Er-169, Yb-175, and Ac-225 with a high specific activity. This article provides a review of the achievements and milestones of CERN-MEDICIS since it has produced its first radioactive isotope in December 2017, with a special focus on its most recent operation in 2020., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Duchemin, Ramos, Stora, Ahmed, Aubert, Audouin, Barbero, Barozier, Bernardes, Bertreix, Boscher, Bruchertseifer, Catherall, Chevallay, Christodoulou, Chrysalidis, Cocolios, Comte, Crepieux, Deschamps, Dockx, Dorsival, Fedosseev, Fernier, Formento-Cavaier, El Idrissi, Ivanov, Gadelshin, Gilardoni, Grenard, Haddad, Heinke, Juif, Khalid, Khan, Köster, Lambert, Lilli, Lunghi, Marsh, Palenzuela, Martins, Marzari, Menaa, Michel, Munos, Pozzi, Riccardi, Riegert, Riggaz, Rinchet, Rothe, Russell, Saury, Schneider, Stegemann, Talip, Theis, Thiboud, van der Meulen, van Stenis, Vincke, Vollaire, Vuong, Webster, Wendt, Wilkins and the CERN-MEDICIS collaboration.)