The Monte Carlo GPT methodology for the analysis of ratios of functionals bilinear with the real and adjoint neutron fluxes
Perturbation methods are part of the reactor physics foundation devoted to the study of fundamental
quantities used in design and safety analysis of nuclear reactors. In deterministic codes, such as
ERANOS, standard perturbation theory (SPT) and generalized perturbation theory (GPT) methods have
been historically developed and used. Monte Carlo codes, such as MCNP 6.1, can also perform, via adjoint
weighted tally, SPT calculations of reactivity worths. In this work a method, referred to as MC-GPT, is
envisaged to enable Monte Carlo codes to be used also for GPT analysis. A preliminary comparison
between calculations with MCNP and ERANOS relevant to perturbations affecting a given reactivity worth
functional is presented and commented.