https://doi.org/10.1051/epjconf/202124704001
ENHANCING THE PERFORMANCE OF FISSION SOURCE CONVERGENCE WITH FUNCTIONAL EXPANSION TALLIES IN SERPENT 2 MONTE CARLO CODE
1 LUT University P.O. Box 20, FI-53851 Lappeenranta, Finland
2 VTT Technical Research Centre of Finland, Ltd. P.O. Box 1000, FI-02044 VTT, Finland
Corresponding author.
Ana.Jambrina@lut.fi
Jaakko.Leppanen@vtt.fi
Heikki.Suikkanen@lut.fi
Published online: 22 February 2021
This paper presents an upgrade to the built-in response matrix based solver implemented in Serpent 2 Monte Carlo code aiming to improve the fission source convergence when obtaining the forward solution to the k-eigenvalue criticality source problems. The functional expansion tallies are introduced in an attempt to improve the accuracy of the cell-wise form factors that feed the response matrix solver, replacing the current mesh-based approach. The functional expansion tallies reconstruct the binning surface and collision tallies, by using high-order series expansion to represent the original and continuous spatial distributions. This new feature is implemented to Serpent 2 and tested by single-assembly and full-core PWR calculations (BEAVRS benchmark). The results show enhanced performance of the convergence acceleration methodology based on an improved initial guess of the fission source.
Key words: Monte Carlo / source convergence / acceleration / Serpent 2 / functional expansion tallies
© The Authors, published by EDP Sciences, 2021
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
