EURISOL Multi-MW Target Station - MAFF Configuration - Neutron Fluxes, Fission Rates, Dose Rates and Activation

The EURISOL (The EURopean Isotope Separation On-Line Radioactive Ion Beam) project aims atproducing high intensity radioactive ion beams produced by neutron-induced fission on fissile targets(235U) surrounding a liquid mercury converter. A proton beam of 1GeV and 4MW impinges on theconverter, generating, by spallation reactions, high neutron fluxes that induce fission in thesurrounding fissile targets.In this work the state-of-the-art Monte Carlo codes MCNPX and FLUKA were used to assess theneutronics performance of the system, which geometry, inspired in the MAFF concept, allows aversatile manipulation of the fission targets. The first objective of the study was to optimize thegeometry and the materials used in the fuel and reflector elements of the system, in order to achievethe highest possible fission rates. Indeed, it is shown that the appropriate combination of fission targetmaterial and surrounding reflector material leads to the aimed value of 1015 fissions/s per fissiontarget. The second part of this work is related to safety parameters. Dose rate and activationcalculations were carried out in order to identify the necessary shielding and access restrictions foreach section of the entire facility, including maintenance, storage and remote control spaces.The results presented in this work indicate that there are good prospects for the feasibility of theEURISOL fission target, in its new configuration, considered in this work. The safety analysisindicates that some points of the facility need special attention from the safety and radioprotectionpoints of view.