PROTEUS is a set of high-fidelity-capable advanced neutronics modeling and simulation tools including cross section generation codes, transport solvers (discrete ordinate (SN), method of characteristics (MOC), and NODAL), and mesh generation toolkit. The SN and MOC solvers are based on unstructured finite element meshes to be able to simulate complex geometries, while the NODAL solver can handle Cartesian and hexagonal geometries. All solvers can solve full transient problems. The code uses multigroup cross sections generated from MC2-3 or Monte Carlo codes (Serpent or OpenMC), and can generate the self-shielded multigroup cross sections on-the-fly using the cross section API. Typical reactor geometry meshes for Cartesian or hexagonal assembly based cores can be easily generated using the mesh generation toolkit.
More information can be found at https://www.ne.anl.gov/codes/proteus.