8. History

ARMI was originally created by TerraPower, LLC near Seattle WA starting in 2009. Its original mission was to determine the optimal fuel management operations required to transition a fresh Traveling Wave Reactor core from startup to an equilibrium state. It started out automating the Argonne National Lab (ANL) fast reactor neutronics codes, MC2 and REBUS. A simple reactor model design was made with the intention of adding other physics capabilities later. Soon, simple thermal hydraulics kernels were added, and it has grown ever since.

Following requests by outside parties to use ARMI, we started working on a more modular architecture for ARMI, allowing some of the intertwined physics capabilities to be separated out as plugins from the standalone framework. ARMI was separated from a codebase designed specifically for just one reactor to a central framework of code used to model generic nuclear reactors.

In 2019, ARMI was released under an open-source license.