Radiation safety with high power operation of EURISOL

The European Community has launched the design study for a next generation RIB facility able to increase by a few orders of magnitude, the exotic beam intensity and availability in Europe. Forty institutes and laboratories within Europe, North America and Asia are taking part in this consortium, named EURISOL DS project (European Isotope Separation On Line Design Study). In EURISOL, four target stations are foreseen, three direct targets of approximately 100 kW of beam power and one multi-MW (MMW) target assembly, all driven by a high-power particle accelerator. In this MMW station, high-intensity RIBs of neutron-rich isotopes will be obtained by inducing fission in several actinide targets surrounding a liquid metal spallation neutron source. The envisaged increase in RIB intensities at EURISOL means a drastic increase of the radioactive inventory and corresponding radioprotection related issues. Safety aspects of the future RIB production targets (aiming at a few ~1015 fissions/s) will become decisive in limiting the beam intensities, in selecting the production method and materials, and in the final cost of the facility. New technical challenges arise that will in most cases also critically affect the safety approval procedures. The handling and disposal of open radioactive high intensity RIB production targets (e.g. UCx, ThCx) including liquid Hg converter target is yet unexplored. Equally, containment of gaseous radioactivity and its migration will be crucial in the same context. The progress made so far on most of these issues within Task 2 "multi-MW target" and Task 5 "Safety and Radioprotection" will be summarized.