Computing adjoint-weighted kinetics parameters in Tripoli-4® by the Iterated Fission Probability method

The analysis of neutron kinetics relies on the knowledge of adjoint-weighted kinetics parameters, which are key to safety issues in the context of transient or accidental reactor behavior. The Iterated Fission Probability (IFP) method allows the adjoint-weighted mean generation time and delayed neutron fraction to be computed within a Monte Carlo power iteration calculation. In this work we describe the specific features of the implementation of the IFP algorithm in the reference Monte Carlo code Tripoli-4® developed at CEA. Several verification and validation tests are discussed, and the impact of nuclear data libraries, IFP cycle length and inter-cycle correlations are analyzed in detail.