Treatments for Neutron Resonance Elastic Scattering Using the Multipole Formalism in Monte Carlo Codes

摘要

This work developed and implemented a modified DBRC algorithm compatible with the multipole resonance formalism in OpenMC. It was shown through a comparison of scattering kernels, average energies after scattering, and upscattering probabilities for resonance scattering with incident neutrons near specific U-238 resonances that the new DBRC-MP method produced accurate results consistent with the previous DBRC-ACE method. Pin-cell eigenvalue simulations were also done, and it was shown that using the WMP format data produced results that agreed with simulations using ACE format data. Taking into account that using multipole alone slowed computation time by roughly 20%, it was shown that DBRC-MP is about as efficient as DBRC-ACE compared to cases where resonance scattering was not treated. While using WMP is still more computationally costly than using the ACE format, WMP reduces memory requirements by a hundred-fold while DBRC-MP preserves accurate treatment of resonance scattering. Future work can be done to couple WMP format data with other resonance scattering treatments, including the Accelerated Resonance Elastic Scattering (ARES) method which was previously implemented in OpenMC using ACE format cross section data.