This repository provides tools for parsing/converting MCNP models to OpenMC classes and/or XML files. To install these tools, run:

python -m pip install git+https://github.com/openmc-dev/openmc_mcnp_adapter.git

This makes the openmc_mcnp_adapter Python module and mcnp_to_openmc console script available. To convert an MCNP model, run:

mcnp_to_openmc mcnp_input

There has been no methodical V&V on this converter; use at your own risk!

The converter currently only handles geometry and material information; source definition (SDEF) and tally specifications are ignored.

The converter will try to set surface boundary conditions to match the MCNP model, but in many cases it doesn't work cleanly. For these cases, you will need to manually set boundary conditions on the outermost surfaces.

Some geometry features are not currently supported:

• Periodic boundary conditions
• X, Y, and Z surfaces with 1 or 3 coordinate pairs
• RHP, REC, ELL, WED, and ARB macrobodies
• Hexagonal lattices
• One-dimensional lattices
• Two-dimensional lattices with basis other than x-y
• U, LAT, and FILL cards specified in the data card block