Recovered Fuels by means of the measuring of 14 C at the plant emission Giovanni Ciceri*, Domenico Cipriano*, Guandalini Roberto*, Costanza Scacchi* Battistina Bianchilli**, Giorgio Catanzani** SEEP 2009 – 3rd International Conference on Sustainable Energy & Environmental Protection Dublino, 12-15 Agosto 2009 * ERSE SpA ** NUCLECO Up to now the biomass content determination of MSW and SRF is obtained through a selection and characterisation of a representative sample of the material burned, nevertheless in recent years international researches have been oriented to the measurement of 14 C level directly at the stack emission. This method appear to be of lower cost, widest applicability and potentially suitable for routine analysis. In this paper we present the results of some experimental campaign carried out in Italy on different plants burning SRF and MSW for power production. Results has been compared with those obtained applying other consolidated methods (e.g. chemico- physical characterisation of fractions separated from MSW by manual sorting). Preliminary results showed that the method is highly promising, but still needs research activity to better understand the response due to different fuel composition and plant operation modality.