Nuclear Science and Engineering / Volume 150 / Number 1 / May 2005 / Pages 109-114
A new SAMMY analysis of the 241Pu resonance parameters from thermal to 20 eV is presented. This evaluation takes into account the trends given by integral experiments [post-irradiation experiments performed in French pressurized water reactors (PWRs)]. Compared to the previous evaluations performed by Derrien and de Saussure, the capture cross section increases especially in the 0.26-eV resonance. It is shown that the new resonance parameters proposed in this work improve the prediction of the 242Pu buildup in a PWR, which was significantly underestimated with the previous evaluations.