A modern, community-driven Monte Carlo particle transport code.

(Monte Carlo N-Particle) for his thesis on modular reactor shielding, but the official path through the Radiation Safety Information Computational Center (RSICC)

If you need a Monte Carlo code for radiation transport but cannot get a license for MCNP, consider these open-source alternatives:

If your work specifically requires MCNP6.2 (e.g., for regulatory compliance or specific nuclear data libraries), you must go through the official channels.

: Popular in reactor physics; it is free for non-commercial and educational use (requires a separate request process). Installing MCNP6.2 on Microsoft Windows

Includes improved calculational efficiency and tools for nuclear safeguards and nonproliferation.