ProfugusMC is a proxy application that strives to represent the complex, random branching execution path typical of Monte Carlo transport.  (See also  XSBench that represents cross section look up in Monte Carlo transport.

Shift is a Monte Carlo solver used in the ECP ExaSMR project. The ExaSMR project’s goal is to bring operational, commercial Small Modular Reactors (SMRs) online. Current reactor simulations rely on an experimental database and constrained design margins. This becomes limiting when experimenting with innovative designs, such as Small Modular Reactors. In order to address this issue ExaSMR aims to simulate the reactor core beyond the beginning of life. In order to accomplish this simulation they will couple the Monte Carlo solver (used for Monte Carlo neutron transport simulation) with a Computational Fluid Dynamics code and utilize the computational power of Exascale systems.