Evaluation of effective kinetic parameters and adjoint flux distribution using iterated fission probability in the iMC Monte Carlo code

Abstract

The iterated fission probability (IFP) method enables assessment of adjoint flux-weighted kinetic parameters, i.e., effective kinetic parameters, in Monte Carlo (MC) simulation, an essential capability in modern MC codes. This method can be extended to calculate adjoint flux-weighted quantities within a prescribed phase-space, enabling the estimation of adjoint flux distributions. The iMC Monte Carlo code, developed at the Korea Advanced Institute of Science and Technology (KAIST), is proficient in both calculating effective kinetic parameters and adjoint flux distributions. This paper presents benchmark results verifying the code's capabilities. Critical device configurations are considered for evaluating kinetic parameters, compared with the Serpent2 code results. Both multi-group and continuous-energy benchmarks are solved to assess IFP-based spatial- and energy-wise adjoint flux distributions, and comparison is made against deterministic transport calculations. Results show that effective kinetic parameters can be accurately estimated, and acceptable adjoint flux distributions can be obtained using the iMC code.