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

TL;DR

This paper extends the open-source Monte Carlo code OpenMC to calculate reactor kinetic parameters, specifically the effective delayed neutron fraction and neutron generation time, providing an accessible alternative to licensed codes.

Contribution

The authors developed OpenMC(TD), a modified version of OpenMC capable of calculating kinetic parameters using prompt and pulsed methods, validated against experimental and MCNP data.

Findings

OpenMC(TD) accurately estimates $eta_{eff}$ and $ au$ for benchmark configurations.

Results are consistent with experimental data and MCNP calculations.

OpenMC(TD) offers a viable open-source tool for reactor kinetic parameter estimation.

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.