Minor Actinides Fuel Neutron Performances

In this document are pointed out the principal results of a neutronic study, focused to the 'better use' of some Minor Actinides (MA) fuel solutions at the 'maximization' purpose of 'incineration' rate. The incineration rate is intended as burning and/or transmutation rate of the MA themselves into other isotopes of reduced radio-toxicity. It is a preliminary physics study, starting from MA fuel compositions coming from pyrometallurgic (electrochemical) process and oriented to the use of a sub critical reactor, of the liquid metal ADS family, as reference reactor in the frame of the prevalent idea to assure high neutron fluxes. However the obtained results show a realization's difficulty of such a reactor concept owing to a not negligible worsening of the safety aspects and performances. Besides this, the increase of the reactivity during the life, transforming the sub critical reactor in a (over) critical reactor, requires the introduction of control systems (like control rods) extraneous to the sub critical reactor concept.