Rossi-alpha Benchmark Validation of a Static Alpha Eigenvalue Capability in OpenMC
Abstract
A static alpha eigenvalue capability was implemented in a modified version of the open-source Monte Carlo radiation transport code OpenMC and validated against Rossi-alpha measurements from 21 delayed-critical benchmark experiments and 33 subcritical configurations spanning fast, intermediate, and thermal systems with U-233, HEU, IEU, LEU, and plutonium fuels. The effective delayed neutron fraction was calculated using the k-prompt method, and the prompt neutron lifetime was calculated using the iterated fission probability method, both evaluated within the standard k-eigenvalue power iteration. The delayed-critical alpha eigenvalue was calculated from these quantities using the point kinetics equation alpha_dc = -beta_eff / ell_p. Agreement was generally within 10% for fast metal systems and within 5% for thermal solution systems. Subcritical extrapolation studies derived from the SHE-8 and STACY benchmark families show that alpha_dc remains stable as the system is driven subcritical.
Related
- QC-Stark: A Multi-Task Benchmark Revealing Capability Dissociations in LLMs Evaluated on Quantum Computing Tasks
- Numerical benchmark to assess sensitivity to spatial discretization in quasi-static fracture simulations : Application to phase-field models
- Photonuclear Neutron Production in OpenMC: Verification Against MCNPX, FLUKA, and a First-Collision Analytical Solution
- Simulating scintillation detector responses with OpenMC and pyMPPost: a track-based coupling verified against MCNPX-PoliMi
- AI's Capability in Assisting Scientific Research in Physics, Astrophysics, and Cosmology I: Literature Review
BibTeX
@misc{zywiec2026rossialpha,
title = {{Rossi-alpha Benchmark Validation of a Static Alpha Eigenvalue Capability in OpenMC}},
author = {William Zywiec and Alessandro Ingegno and David Heinrichs and Benoit Forget},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2606.00907},
eprint = {2606.00907},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.00907},
}
RIS
TY - UNPB
TI - Rossi-alpha Benchmark Validation of a Static Alpha Eigenvalue Capability in OpenMC
AU - William Zywiec
AU - Alessandro Ingegno
AU - David Heinrichs
AU - Benoit Forget
PY - 2026
DA - 2026/10/16
PB - arXiv
DO - 10.48550/arxiv.2606.00907
UR - https://arxiv.org/abs/2606.00907
AB - A static alpha eigenvalue capability was implemented in a modified version of the open-source Monte Carlo radiation transport code OpenMC and validated against Rossi-alpha measurements from 21 delayed-critical benchmark experiments and 33 subcritical configurations spanning fast, intermediate, and thermal systems with U-233, HEU, IEU, LEU, and plutonium fuels. The effective delayed neutron fraction was calculated using the k-prompt method, and the prompt neutron lifetime was calculated using the iterated fission probability method, both evaluated within the standard k-eigenvalue power iteration. The delayed-critical alpha eigenvalue was calculated from these quantities using the point kinetics equation alpha_dc = -beta_eff / ell_p. Agreement was generally within 10% for fast metal systems and within 5% for thermal solution systems. Subcritical extrapolation studies derived from the SHE-8 and STACY benchmark families show that alpha_dc remains stable as the system is driven subcritical.
ER -