Multiphysics Coupling Along a Nuclear Fuel Rod With Single-batch Monte Carlo
Miriam Kreher, Massachusetts Institute of Technology
Nuclear reactors represent a unique intersection of many fields including quantum physics in the fuel, mechanical engineering in the boiler and materials science in the fuel performance and plant components. This work focuses on the feedback effects between neutronics and thermal-hydraulics in the core. Although coupling between Monte Carlo and subchannel codes has been done many times and in many forms, it has not necessarily been done well. There still remain many open questions about assessing convergence and overcoming instabilities.
The subchannel code provides temperature distribution information through the enthalpy rise along a fuel rod, then the Monte Carlo code uses that information to determine the power distribution in the fuel using temperature-dependent cross-sections. Recent work at Naval Nuclear Laboratories has determined that the convergence of the coupled system is independent of the convergence of the Monte Carlo simulation. As a result, this work explores the single-batch simulation of neutronics in a steady-state multiphysics calculation as a form of under-relaxation.
Abstract Author(s): Miriam A. Kreher, Ben Forget, Kord Smith