title: Opensource alternative for MCNP Monte Carlo simulation
body: <p><a href="https://mcnp.lanl.gov/" rel="nofollow">MCNP</a> (Monte Carlo N-Particle) is a quite old but famous Fortran code to simulate radiation effects with Monte Carlo calculations. It can be used for radiation safety calculations.</p>
  
  <p>It is very difficult and expensive to get the MCNP suite and the code is very hard to read.</p>
  
  <p>What is an open source alternative for MCNP?</p>