Monte Carlo power iteration: Entropy and spatial correlations
Name
Forget_Monte Carlo power iteration.pdf
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1.14 MB
Format
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Checksum (MD5)
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Author(s)
Nowak, Michel
Dumonteil, Eric
Onillon, Anthony
Zoia, Andrea
Miao, Jilang
Forget, Benoit Robert Yves
Smith, Kord S.
Date Issued
May 2016
Journal
Annals of Nuclear Energy
Publisher
Elsevier BV
Citation
Nowak, Michel et al. “Monte Carlo Power Iteration: Entropy and Spatial Correlations.” Annals of Nuclear Energy 94 (August 2016): 856–868 © 2016 Elsevier Ltd
Version
Author's final manuscript
Abstract
The behavior of Monte Carlo criticality simulations is often assessed by examining the convergence of the so-called entropy function. In this work, we shall show that the entropy function may lead to a misleading interpretation, and that potential issues occur when spatial correlations induced by fission events are important. We will support our analysis by examining the higher-order moments of the entropy function and the center of mass of the neutron population. Within the framework of a simplified model based on branching processes, we will relate the behavior of the spatial fluctuations of the fission chains to the key parameters of the simulated system, namely, the number of particles per generation, the reactor size and the migration area. Numerical simulations of a fuel rod and of a whole core suggest that the obtained results are quite general and hold true also for real-world applications. Keywords: Entropy; Clustering; Power iteration; OpenMC; Tripoli-4®
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1016/J.ANUCENE.2016.05.002
