Current Inconsistencies in 238Pu, 241,243Am and 242Cm Evaluations and their Impact on Uncertainties

Improvements in the nuclear reaction modeling and nuclear parameter systematics, consistent with the description of neutron data on major actinides 232Th, 233U, 235U, 238U and 239Pu will be shown to provide a sound basis for critical assessment of the fission, capture, inelastic scattering, and (n,xn) reaction cross sections on minor actinides. This will largely help to avoid substituting possible model deficiencies by enlarging parameter uncertainties in the conventional nuclear models. In a number of minor actinides, the uncertainty estimation of cross sections and prompt fission neutron spectra would require complete re-evaluation of basic data. Otherwise, extremely large cross section uncertainty estimates will have to be adopted, especially in the case of poorly investigated Np, Pu, Am, Cm targets.