Institute for Neutron Physics and Reactor Technology (INR)

Monte Carlo Methods

Reactor Safety: Monte Carlo based High-Fidelity Methods

The goal of Monte Carlo based high fidelity methods is to perform simulations of pin/fuel assembly clusters or whole cores using Monte Carlo codes and taking into account local thermal hydraulic conditions predicted by subchannel codes. Such developments are needed due to:

  • Lack of experimental data about local safety relevant parameters of reactor cores e.g. pin power, cladding temperature, fuel temperature, etc.
  • Available computer power (HPC) and parallel capability of MC and TH codes, paves the way for very-detailed coupled Neutronic/TH simulations not possible before

Optimized high fidelity MC/TH simulations will deliver:

  • Reference solutions to check deterministic codes e.g. for power distribution, depletion problems taking into account thermal hydraulic feedbacks


  KIT MCNP/SUBCHANFLOW System: Main Features
  • Internal coupling
  • Uniform convergence
  • Stochastic approximation convergence acceleration
  • On-the-fly T-interpolation of XS
  • Variance reduction with an iterative flux-based Weight Window technique
  • Accelerated tallying with custom written Collision Density and Track-Length estimators
  • Parallelization of MCNP and SCF with hybrid MPI/OpenMP
  • Utilization of HPC - Blue Gene/Q