Regular Article

Scarabée: A Free and Open-Source Lattice Physics Code

¹ Université Paris-Saclay, CEA, Service d’Études des Réacteurs et de Mathématiques Appliquées, 91191 Gif-sur-Yvette, France
² Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th St., Troy, NY, USA

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Received: 11 February 2026
Received in final form: 28 March 2026
Accepted: 4 April 2026
Published online: 8 June 2026

Abstract

Scarabée is a new free and open source deterministic neutron transport toolkit. It is used as a Python library, giving access to a variety of 1D and 2D transport solvers, as well as 3D diffusion solvers. It also provides a PWR lattice physics calculation scheme, which automates the self-shielding and depletion calculations of standard PWR assemblies, including advanced features to handle Gadolinia depletion. Users can also write their own computational schemes to suit their particular needs. While users can provide cross sections, it can also use a custom HDF5 formatted multi-group nuclear data library, which is designed for self-shielding calculations based on equivalence in dilution. Scarabée is released under the LGPLv3 license, and can be installed via pip on all major operating systems, making it an excellent choice for use in teaching reactor physics.