[en] A Swiss research consultancy Resonance on the evaluation of the seismic risk of the nuclear power plant of Fessenheim and on the seismic sizing of this installation concluded ( 2007) that the revaluation of the seismic risk proposed by EDF for the third ten year visit (2009) led to an under estimation of the risk and then was not acceptable. However, Resonance estimated that it was impossible to conclude that the nuclear power plant of Fessenheim represents an unacceptable seismic risk even if a suspicion was allowed.The authors of this report judged imperative to proceed the most quickly as possible to a deep seismic checking of the buildings and installations. Resonance transmitted its report to I.R.S.N. that made of it a detailed analysis. The object of the present document is to present the comments of I.R.S.N. on the points considered as significant in this report. (N.C.)