Uncertainty and correlation analysis of lead nuclear data on reactor parameters for the European Lead Cooled Training Reactor

The Total Monte Carlo (TMC) method was used in this study to assess the impact of 204,206,207,208Pb nuclear data uncertainties on reactor safety parameters for the ELECTRA reactor. Relatively large uncertainties were observed in the keff and the coolant void worth (CVW) for all isotopes except for 204Pb with significant contribution coming from 208Pb nuclear data; the dominant effect came from uncertainties in the resonance parameters; however, elastic scattering cross section and the angular distributions also had significant impact. It was also observed that the keff distribution for 206,207,208Pb deviates from a Gaussian distribution with tails in the high keff region. An uncertainty of 0.9% on the keff and 3.3% for the CVW due to lead nuclear data were obtained. As part of the work, cross section-reactor parameter correlations were also studied using a Monte Carlo sensitivity method. Strong correlations were observed between the keff and (n,el) cross section for all the lead isotopes. The correlation between the (n,inl) and the keff was also found to be significant.