MCNP review
A self-hosted Monte Carlo transport code for detailed radiation and particle simulations.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
MCNP is a general-purpose Monte Carlo code for modeling how neutrons, photons, electrons, ions and other particles move through three-dimensional material geometries. Developed and maintained by the MCNP team at Los Alamos National Laboratory, it is suited to technical teams working on radiation shielding, dosimetry, medical physics, criticality safety or reactor design. Its focus is particle transport rather than discrete-event, system-dynamics, agent-based or finite-element simulation, so teams seeking those paradigms should look elsewhere.
Its modeling toolkit covers constructive solid geometry and hybrid mesh geometry, with fixed-source and k-eigenvalue solution modes. Users can calculate surface, volume, mesh, radiography, heating and pulse-height tallies, along with statistical uncertainties. Variance-reduction techniques address simulation efficiency, while geometry and tally-output plotters help inspect models and results. Parallel execution is supported through OpenMP and MPI. This breadth makes MCNP a fit for specialist transport work, but not a general simulation environment spanning unrelated modeling approaches.
MCNP runs on Windows, macOS and Linux and is self-hosted. Distribution is controlled and handled through RSICC for users outside LANL, under export-control requirements, which is an important consideration for organizations evaluating access. The pricing model is contact sales; published plan details are not part of the offering described here. Documentation and email are the listed support channels. Teams with the expertise and need for particle-transport modeling may find its specialized modes and tallies relevant; organizations wanting cloud deployment, a broad suite of simulation paradigms, or an unrestricted route to distribution should consider alternatives.
MCNP pros and cons
- Where it wins
- Models neutrons, photons, electrons, ions and other particles
- Supports 3D constructive solid and hybrid mesh geometry
- Offers varied tallies, variance reduction, and OpenMP/MPI execution
- Where it doesn't
- Distribution is controlled and handled through RSICC outside LANL
- Requires self-hosted deployment
- Pricing is handled through contact with sales
MCNP fact sheet, pricing and score →
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