The influence of the neutron source spectrum on the infinite homogeneous reactor in subcritical condition

An analysis of the influence of the neutron source spectrum on some key parameters of a reactor system in subcritical condition is presented. The analysis is conducted on the infinite homogeneous reactor, a kind of approach useful to have a quick understanding of nuclear reactor phenomena. The main differences between the spectrum in critical and subcritical condition are highlighted. Among the results of the analysis we present the impact on the multiplication factor of neglecting the delayed neutron spectrum. The homogenization error on few-group cross sections due to using critical spectra in the standard homogenization procedures is also discussed.