Minor actinides transmutation in the EFIT Reactor: A design challenge

In the EUROTRANS Integrated Project, funded by the European Union (EU), within the 6th FP (Framework Program), the conceptual feasibility of high rate MA transmutation in ADS has been demonstrated: this concept reactor is called EFIT (European Facility on Industrial scale Transmuter). It is fuelled by Cer-Cer (Pu, MA)O2-x + MgO fuel type with high content of MA and is cooled by lead. The design constraints for the maximum temperatures of the cladding and of the fuel are satisfied through the power distribution radial flattening techniques. The conceptual design of the EFIT core is based on the so called '42-0' approach, characterized by zero Pu net balance and maximum MA transmutation rate of 42 kg/TWhth with reduced BU reactivity loss (∼200 pcm/year). Three radial zones, for a total of 180 FAs, at constant Pu/MA mass ratio and with different either pin diameter and/or inert matrix volume fraction, assure the required value for the sub-criticality level Keff= 0.97. The total power of 384 MWth is driven by a proton beam (Ep = 800 MeV) with (almost constant) current never exceeding 15 mA. Neutronic evaluations have been carried out in ENEA by both deterministic (ERANOS) and Monte Carlo (MCNP(X)) codes. The T/H analysis, performed at FZK, shows acceptable maximum temperatures. (authors)