Calculation of kinetic parameters $\beta_{\mathit{eff}}$ and $\Lambda$ with modified open source Monte Carlo code OpenMC(TD)

Abstract

This work presents the methodology used to expand the capabilities of the Monte Carlo code OpenMC for the calculation of reactor kinetic parameters: effective delayed neutron fraction $\beta_{\mathit{eff}}$ and neutron generation time $\Lambda$. The modified code, OpenMC(Time-Dependent) or OpenMC(TD), was then used to calculate the effective delayed neutron fraction by using the prompt method, while the neutron generation time was estimated using the pulsed method, fitting $\Lambda$ to the decay of the neutron population. OpenMC(TD) is intended to serve as an alternative for the estimation of kinetic parameters when licensed codes are not available. The results obtained are compared to experimental data and MCNP calculated values for $18$ benchmark configurations.