International audienceABSTRACT. The seismic margins assessment of the nuclear plants is a priority for the whole nuclear community, further enhanced since the Tohoku Japan earthquake in 2011. In this framework a 5 years research project called SINAPS@ (Earthquake and 9ème Colloque National AFPS 2015 – IFSTTAR 2 Nuclear Plants: Ensuring and Sustaining Safety) is currently ongoing in France. A reliable estimate of seismic margins is possible only if all uncertainties, epistemic and aleatory, are effectively identified, quantified and integrated in the seismic risk analysis. SINAPS@ brings together a multidisciplinary community of researchers and engineers from the academic and nuclear worlds. SINAPS@ aims at exploring the uncertainties associ...