A curated list of open source projects used in nuclear science and engineering.

• ERGnrc — Monte Carlo photon/electron/positron transport code
• FRENSIE — Monte Carlo neutron/photon transport code
• Geant4 — High-energy Monte Carlo particle transport code
• OpenMC — Monte Carlo neutron/photon transport code
• SCONE — Monte Carlo neutron transport code
• Warp — Monte Carlo neutron transport code on GPUs

• BART — Finite-element, discrete ordinates code developed by UC-Berkeley
• Chi-Tech — Parallel discrete ordinates code developed by Texas A&M
• DRAGON — Lattice code developed by Polytechnique Montreal
• FeenoX — Unstructured finite-element(ish) tool, diffusion and discrete ordinates
• OpenMOC — Method of characteristics code
• THOR — Discrete ordinates code using the AHOT-C method on unstructured meshes

• CGMF — Fission event generator
• FREYA — Fission event generator

• ACE Format — Documentation of the ACE format
• csg2csg — Tool to translate between different CSG types
• DAGMC — Direct accelerated geometry Monte Carlo toolkit
• KDSource - A tool for generating KDE surface sources from Monte Carlo simulations
• McCAD — CAD (BRep) to Monte Carlo (CSG) Conversion Tool
• MCNPTools — C++/Python interface and tools for MCNP
• MCPL — Binary file format for storing particle state
• MontePy — Python library to read, edit, and write MCNP files
• serpentTools — Python-based tool suite for Serpent
• t4_geom_convert — Convert MCNP geometries to TRIPOLI-4

• ACEMAKER — Code package to produce ACE files
• EMPIRE — Nuclear reaction model code
• endf-python — Python ENDF Parser
• FRENDY — Nuclear data processing
• FUDGE — Python-based nuclear data processing
• JADE — Tool for nuclear data library V&V
• mendeleev — Python package for accessing properties of elements, ions, and isotopes
• NJOY21 — Nuclear data processing
• Nuclear Data Reader — C++ library for parsing NUBASE and AME data files
• NucML — Machine-learning pipeline for nuclear data evaluation
• PapillonNDL — C++ / Python library for reading and sampling ACE files
• PREPRO — Nuclear data processing
• PyNjoy 2012 — Nuclear data processing
• SANDY — Sampling tool for nuclear data
• SCALE — Public components of SCALE (AMPX, SAMMY)
• TALYS — Nuclear Reaction Simulator Code

• ADDER — Python-based fuel management and depletion tool
• ALARA — Activation code widely used for fusion
• ONIX — Python-based burnup code
• OpenMC — Depetion solver integrated in OpenMC
• radioactivedecay — Radioactive decay solver

• KOMODO — Nuclear reactor simulator that solves 3-D diffusion using nodal methods
• PyRK — Neutronic and thermal hydraulic reactor transient analysis in 0-D
• Research Reactor Simulator — Real-time GUI research reactor simulator based on point kinetics

• Cyclus — Nuclear fuel cycle simulator

• DASSH — Subchannel thermal fluids code for hexagonal assemblies
• Nek5000 — Spectral-element CFD code
• nekRS — Spectral-element CFD code targeting modern processors and accelerators
• OpenFOAM — Finite volume CFD code
• TrioCFD — A Computational Fluid Dynamics (CFD) code based on the TRUST platform.

• Aurora — OpenMC wrapped as a MOOSE app
• Cardinal — OpenMC and nekRS wrapped as MOOSE apps
• ENRICO — Monte Carlo + CFD coupling application
• GeN-Foam — OpenFOAM based multi-physics solver for reactor analysis
• MOOSE — Finite-element, multiphysics framework
• SALOME — Interoperability between CAD and multiphysics software
• TRUST — A software platform upon which CFD codes can be built

• Moltres — A molten salt reactor simulator code
• MSRE — Detailed CAD model of the MSRE
• SaltProc — Fuel reprocessing simulation tool

• ARMI — Reactor analysis automation framework
• NRIC Virtual Test Bed — Repository of example challenge problems
• PyNE — Python/C++ nuclear engineering toolkit
• RAVEN — UQ, regression, PRA, data analysis, and model optimization framework
• WATTS — Python-based tool for templated simulations
• LaTeX classes and BibTeX style for ANS publications

• ARFC (UIUC) — Advanced Reactors and Fuel Cycles
• CNERG (UW-Madison) — Computational Nuclear Engineering Research Group
• CRPG (MIT) — Computational Reactor Physics Group
• ONCORE (IAEA) — an IAEA-facilitated international collaboration framework for the development and application of open-source multi-physics simulation tools to support research, education and training for the analysis of advanced nuclear power reactors.