A Spatially Variant Rebalancing Method forDiscrete-Ordinates Transport Equation

W. Ford (1, 2) , E. Masiello (1, 2) , C. Calvin (2, 1) , F. Févotte (3) , B. Lathuilliere (3)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
2 SERMA - Service d’Études des Réacteurs et de Mathématiques Appliquées
3 EDF - EDF

In this paper we propose a new non-linear technique for accelerat-ing source iterations for the discrete-ordinates transport equation. Themethod, called Spatially Variant Rebalancing Method (SVRM), is basedon the computation of the zero and first order spatial variation of theneutron balance equation. The non-linear acceleration is applied to themethod of characteristics (MOC) with a step-approximation of the source.The new acceleration is meant to catch high-order variation of the neutronflux within the spatial mesh. The paper proposes a numerical analysis ofthe technique based on the explicit computation of the Jacobian. Thelatter is analyzed with both spectral and Fourier analysis. Also, a com-parison of the new method with CMFD, DSA, and BPA has been donefor a parametrized heterogeneous problem that allows the study of theperformances of the method in different transport regimes.

Keywords: Coarse-mesh Rebalancing; Discrete Ordinates Transport Equation; Diffusion Synthetic Acceleration; Coarse-Mesh Finite Differences

Domains: Nuclear Experiment [nucl-ex]; Nuclear Theory [nucl-th]

W. Ford, E. Masiello, C. Calvin, F. Févotte, B. Lathuilliere. A Spatially Variant Rebalancing Method forDiscrete-Ordinates Transport Equation. Annals of Nuclear Energy, 2019, 133, pp.589-602. ⟨10.1016/j.anucene.2019.06.046⟩. ⟨cea-02339871⟩