A 2D/1D algorithm for effective cross sections generation in fast reactor neutronic transport calculations

B. Faure (1) , P. Archier (1) , J.-F. Vidal (1) , L. Buiron (1)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)

Fast resolution of the Boltzmann transport equation over a nuclear reactor core presupposes the definition of homogenized and energy collapsed cross sections. In modern sodium fast reactors that rely on heterogeneous core designs, anisotropy in the neutrons propagation cannot be neglected so three-dimensional models should be used to produce those effective cross sections. In this paper, the 2D-1D approximation is used to avoid computationally expensive 3D calculations while preserving consistent angular representations of the neutron flux. An iterative procedure is defined to solve the 2D-1D equations and produce coarse group homogenized cross sections that preserve 3D transport effects. Accuracy of the algorithm is tested on a realistic model of the ASTRID core showing very good results against Monte Carlo simulations for all neutronic parameters (eigenvalue, sodium void worth and fission map distribution).

Mots clés: Neutronics; Transport; 2D/1D method; Homogenization; Energy condensation; SFR

Domaines: Physique Nucléaire Expérimentale [nucl-ex]; Physique Nucléaire Théorique [nucl-th]

B. Faure, P. Archier, J.-F. Vidal, L. Buiron. A 2D/1D algorithm for effective cross sections generation in fast reactor neutronic transport calculations. Nuclear Science and Engineering, 2018, 192, pp.40-51. ⟨cea-02339778⟩