# openmc-dev/openmc

OpenMC Monte Carlo Code

Repository: https://github.com/openmc-dev/openmc
Canonical: https://ross.abutalabs.com/products/openmc
Homepage: https://docs.openmc.org
Language: Python
License: NOASSERTION
License Family: other
Topics: monte-carlo-simulation, particle-transport, nuclear-engineering, nuclear-energy, nuclear-fusion, openmc, neutronics, photon-transport, neutron-transport, radiation-transport, computational-physics, high-performance-computing, nuclear-data
Last push: 2026-09-02T16:38:52+00:00

## Health v2 (maintenance only)
Score: 87/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 100, release rhythm 64, longevity 100
- inputs: {"age_days": 5523, "days_push": 0, "days_rel": 28, "gap_med": 248, "n_releases_24m": 4}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1093, forks 676 (observed 2026-09-03T02:15:15.816188+00:00)

## What it is
OpenMC is a Monte Carlo particle transport code for simulating neutron and photon transport in constructive solid geometry using continuous-energy HDF5 cross sections. It combines a C++ simulation kernel with a Python API for building models, running simulations, and analyzing results.

## Use cases
- simulate neutron transport in a nuclear reactor core
- run Monte Carlo radiation transport calculations
- compute k-eigenvalues and reaction rates for reactor physics
- model shielding and photon transport problems
- perform neutronics analysis for fusion blankets
- build parametric reactor models with the Python API
- use continuous-energy nuclear data in HDF5 format for simulations

## When to choose
- you need an open-source Monte Carlo code for neutron or photon transport
- you want a scriptable Python API for building and running particle transport models
- you need continuous-energy transport with constructive solid geometry
- you are doing reactor physics, fusion neutronics, or shielding research
- you want a code that scales to high-performance computing clusters

## When to avoid
- you need deterministic transport methods rather than Monte Carlo
- you need coupled multiphysics simulation out of the box
- you want a GUI-driven tool with no programming
- your application is unrelated to radiation or particle transport

## Facets
- artifact type: library
- maturity: active
- function: simulation, math, sdk, developer-tools
- domain: simulation
- platform: windows, python, cpp, cross-platform
- tags: monte-carlo, particle-transport, neutronics, radiation-transport, nuclear-engineering, reactor-physics, hdf5, constructive-solid-geometry, hpc, physics, computational-physics, high-performance-computing, linux, macos

## Member repositories
- openmc-dev/openmc (main) score 87

## Provenance
- Observed fields: from GitHub, fetched 2026-09-03T02:15:15.816188+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:49:28.955669+00:00, confidence not recorded.
  - readme: https://github.com/openmc-dev/openmc (fetched 2026-09-03T02:15:15.816188+00:00, sha 797a76395278)
- Data as of 2026-08-30T08:39:29.467469+00:00.